A general method of derivitizing and selecting fragments of CD4 peptides that exhibit enhanced (relative to the original fragment) capacity to modulate a CD4-dependent virus-induced cellular response is described. In one aspect, peptide compositions compr...

This invention relates to peptides having antiviral properties. The antiviral peptides comprise membrane transiting peptides, and active fragments and derivatives of such peptides. The antiviral peptides exhibit activity against a broad spectrum of viruse...

Collisional fragmentation of protonated short peptides taking place in a linear quadrupole trap of a mass spectrometer is considered. A model of the fragmentation process is proposed which accounts for the collisional heating of the peptides due to the presence of a buffer inert gas. Dominant ...

Disclosed are scaffolded maleimide clusters, methods of making said clusters and use of said clusters as templates for multivalent peptide assembly. Multiple maleimide functionalities were introduced onto a scaffold molecule by the reaction of a core-centered polyamines with methoxycarbonylmaleimide or with activated esters of maleimide-containing compounds. The scaffolded ...

Aug 1, 2005 ... For biological molecules, MALDI TOF-MS can detect DNA/RNA fragments, whole proteins and peptides and digested protein fragments. ...

For biological molecules, MALDI TOF-MS can detect DNA/RNA fragments, whole proteins and peptides and digested protein fragments. ...

... N N Mass Spectrometers identify peptides by fragmenting along the amide backbone Page 16. Fragmentation occurs along the backbone revisited ...

A novel ion dissociation technique, which is capable of providing an efficient fragmentation of peptides at essentially atmospheric pressure conditions, is developed. The fragmentation patterns observed often contain c-type fragments that are specific to ECD/ETD, along with the y-/b- fragments ...

The focus of this research is to generate and characterize novel human antibody fragments (Fabs) and peptides that bind breast cancer cells. A combinatorial approach is being taken to generate immunoglobulin Fab that recognize a specific determinant on br...

The focus of this research is to generate and characterize novel human antibody fragments (Fabs) and peptides that bind breast cancer cells. A combinatorial approach is being taken to generate immunoglobulin Fab that recognize a specific determinant on br...

Electron capture dissociation (ECD) of a series of five residue peptides led to the observation that these small peptides did not lead to the formation of the usual c/ z ECD fragments, but to a, b, y, and w fragments. In order to determine how general this behavior is for small sized peptides, ...

... Title : Combinatorial Approach to the Isolation of Human Antibody Fragments and Peptides to Breast Carcinomas. Descriptive Note : Annual rept. ...

... Title : Combinatorial Approach to the Isolation of Human Antibody Fragments and Peptides to Breast Carcinomas. Descriptive Note : Annual rept. ...

... Title : Combinatorial Approach to the Isolation of Human Antibodies Fragments and Peptides to Breast Carcinomas. Descriptive Note : Final rept. ...

The influence of charge distribution on the cleavage of the peptides was investigated by fragmentation efficiency curves and quantum chemical calculations in order to clarify the fragmentation mechanism in this paper. The peptide Arg-Gly-Asp-Cys (RGDC) was oxidized to change the charge distribution, but its main ...

We report a photolabile linker compatible with Fmoc solid phase peptide synthesis and Cu(I)-catalyzed alkyne�azide cycloaddition that allows photochemical cleavage to afford a C-terminal peptide fragment with a native amino terminus.

We report a photolabile linker compatible with Fmoc solid phase peptide synthesis and Cu(I)-catalyzed alkyne-azide cycloaddition that allows photochemical cleavage to afford a C-terminal peptide fragment with a native amino terminus. PMID:21046030

The goal of this project is to design and test novel synthetic peptides that can be cleaved by the extracellular enzyme Prostate Specific Antigen (PSA) to yield a peptide fragment that can enter cells and directly induce apoptosis. The objective is to exp...

We have developed a geometric clustering algorithm using backbone phi,psi angles to group conformationally similar peptide fragments of any length. By labeling each fragment in the cluster with the level-specific Gene Ontology 'molecular function' term of its protein, we are able to compute statistics for molecular function-propensity ...

Tryptic peptides are the analytes of choice for mass spectrometric analysis of protein and peptide as they display a favorable fragmentation pattern due to the presence of a C-terminal basic amino acid residue. Clean y fragment ion series is most commonly observed for these species. In contrast, non-tryptic ...

The reaction of a peptide featuring a bis(2-sulfanylethyl)amino (SEA) group on its C-terminus with a cysteinyl peptide in water at pH 7 and 37 �C leads to the chemoselective and regioselective formation of a native peptide bond. This method called SEA ligation enriches the native peptide ligation repertoire ...

Derivatization procedures for peptides are described that can be performed with sub-picomolar amounts of sample and that are able to direct the formation of fragment ions in Postsource Decay (PSD) MALDI mass spectrometry. Location of a fixed charge (a quarternary ammonium ion) at the N-terminus of a peptide and modification of internal ...

After rabies virus glycoprotein was treated with CNBr, the peptide mixture was fractionated by preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis. CNBr-cleaved peptide fragments were resolved into seven peptide bands under reducing conditions and six peptide bands under ...

We used monoclonal antibody, generated against N-acetylglucosaminyl-beta1-4-N-acetylmuramyl-alanyl-D-isoglutamine (GMDP), and phage display libraries of random peptides to select for oligopeptides, that mimic GMDP in their biological activity. Selected phage clones displayed a peptide RVPPRYHAKISPMVN (called RN-peptide) on their ...

An improved method of de novo peptide sequencing based on mass spectrometry using novel N-terminal derivatization reagents with high proton affinity has been developed. The introduction of a positively charged group into the N-terminal amino group of a peptide is known to enhance the relative intensity of b-ions in product ion spectra, allowing the easy ...

The total synthesis of the 43 amino acid antibacterial peptide Microcin B17 (MccB17) is described. The natural product was synthesized via a convergent approach from a heterocycle-derived peptide and peptide thioester fragments prepared via Fmoc-strategy solid phase peptide synthesis (SPPS). ...

In-source decay (ISD) is a rapid fragmentation occurring in the matrix-assisted laser desorption/ionization (MALDI) source before the ion extraction. Despite the increasing interest for peptides de novo sequencing by ISD, the influence of the matrix and of the peptide itself is not yet fully understood. Here we compare matrices with ...

MALDI-TOF-TOF and de novo sequencing were employed to assess the Tityus serrulatus venom peptide diversity. Previous works has shown the cornucopia of molecular masses, ranging from 800 to 3000Da, present in the venom from this and other scorpions species. This work reports the identification/sequencing of several of these peptides. The majority of the ...

Peptides, either as protein fragments or as naturally occurring entities are characterized by their sequence and function features. Many times the researchers need to massively manage peptide lists concerning protein identification, biomarker discovery, bioactivity, immune response or other functionalities. We present a web server that ...

The 81-residue fragment (F(III)) obtained from bovine carboxypeptidase A after cleavage with cyanogen bromide has been digested by thermolysin and the resulting peptides were isolated. Three of the peptides have been completely structured by Edman degrada...

When collision induced dissociation is used to fragment phosphorylated peptides during tandem mass spectrometry (MS2), an ion exhibiting the neutral loss of phosphoric acid can be the major product. The neutral loss ion can then be fragmented during MS3 for additional resolution of the peptide sequ...

Amyloid Fibril Formation by A16-22, a Seven-Residue Fragment of the Alzheimer's -Amyloid Peptide with Alzheimer's disease, is shown by electron microscopy to form highly ordered fibrils upon incubation that these are amyloid fibrils. The peptide conformation and supramolecular organization in A16-22 fibrils

Systematic investigation of cellular process by mass spectrometric detection of peptides obtained from proteins digestion or directly from immuno-purification can be a powerful tool when used appropriately. The true sequence of these peptides is defined by the interpretation of spectral data using a variety of available algorithms. However ...

Peptide splicing allows the production of antigenic peptides composed of two fragments initially non-contiguous in the parental protein. The proposed mechanism of splicing is a transpeptidation occurring within the proteasome. Three spliced peptides, derived from FGF-5, melanoma protein gp100 and nuclear protein ...

Peptide chemical ligation chemistries, which allow the chemoselective coupling of unprotected peptide fragments, are useful tools for synthesizing native polypeptides or unnatural peptide-based macromolecules. We show here that the phenylthiocarbonyl group can be easily introduced into peptides ...

The gas-phase free radical initiated peptide sequencing (FRIPS) fragmentation behavior of o-TEMPO-Bz-conjugated peptides with an intra- and intermolecular disulfide bond was investigated using MS(n) tandem mass spectrometry experiments. Investigated peptides included four peptides with an ...

Secondary fragmentations of three synthetic peptides (human ?A crystallin peptide 1-11, the deamidated form of human ?B2 crystallin peptide 4-14, and amyloid ? peptide 25-35) were studied in both electron capture dissociation (ECD) and electron transfer dissociation (ETD) mode. In ECD, in ...

157 nm photodissociation of N-linked glycopeptides was investigated in MALDI tandem time-of-flight (TOF) and linear ion trap mass spectrometers. Singly-charged glycopeptides yielded abundant peptide and glycan fragments. The peptide fragments included a series of x-, y-, v- and w- ions with the glycan remaining ...

This account summarizes the energetics and dynamics of peptide fragmentation obtained using a new approach recently developed in our laboratory. The approach involves RRKM modeling of time- and energy-resolved MS/MS data obtained using collisional activation. We demonstrate that surface-induced dissociation (SID) on a long timescale of Fourier transform ...

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 v #12;vi CONTENTS 4 Fragmentation of � and �alanine molecules by ions at Bragg�peak energies 39 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 5.3.2 �alanine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 5.3.3 �valine

and alkylation were found to go to completion with DTT and the nonionic sulfhydryl alkylation reagent the cyano- gen bromide fragments and posttranslational modifi- cations of reduced and alkylated bovine on six of the peptides. After trypsin digestion and HPLC in the detergent octyl glucoside and MALDI

The invention is directed to isolated protein fragments of p62 nucleoporin including deletion isoforms and nucleic acid sequences encoding these deletion isoforms. The invention is also directed to peptides which are at least 80% identical over their enti...

During fatty acid synthesis the incoming two carbon fragment is introduced as the three-carbon malonyl group. It is added to the -SH group of the acyl carier peptide domain of fatty acid synthase. In a subsequent reaction the carbon shown in green will be lost as bicarbonate ion.

The cell recognition of globular proteins requires the uptake and intracellular processing of the native Ag by an APC to produce a peptide fragment containing the T cell antigenic determinant, which is recognized in conjunction with Ia. This report descri...

Catalytic immunoglobin fragments were studied Nuclear Magnetic Resonance spectroscopy to identify amino acid residues responsible for the catalytic activity. Small, hybrid sequence peptides were analyzed for helix propagation following covalent initiation...

Fingerprint analyses of the F fragments and A chains of 22 subjects of different Gm types have demonstrated the presence of a peptide spot in (a+) subjects which cannot be seen in (a-) proteins, and another spot in (b+) proteins which is lacking in (b-) s...

In this paper, a general procedure is described for the generation of peptide maps of proteins with monolithic silica-based columns. The peptide fragments were obtained by tryptic digestion of various cytochrome c species with purification of the tryptic fragments achieved by reversed-phase high-performance liquid ...

The present invention relates to PTH(1-28) peptides and derivatives thereof. Compounds of the invention which include PTH(1-28) peptides, fragments thereof, derivatives thereof, pharmaceutically acceptable salts thereof, and N- or C-derivatives thereof, a...

The use of mass spectrometry coupled with chemical cross-linking of proteins has become one of the most useful tools for proteins structure and interactions studies. One of the challenges in these studies is the identification of the cross-linked peptides. The interpretation of the MS/MS data generated in cross-linking experiments using N-hydroxy succinimide esters is not ...

Peptide mapping has demonstrated that gamma globulins of different Gm types differ in primary structure. A single peptide present in Gm(a +) H chains and F fragments is lacking in the corresponding Gm (-) structural subunits; similarly, the presence of a ...

Antigen-binding fragments (Fab) of mouse monoclonal antibodies to human interleukin-2 were obtained in preparative quantities by a modified procedure. These Fab-fragments were shown to be homogeneous according to the isoelectric focusing method. Various monocrystals of these free Fab-fragments and their complexes with the antigenic ...

... interpretation of peptide fragmentation spectra acquired by postsource decay (PSD) analysis on a MALDI-TOF mass spectrometer or by tandem mass spectrometry (MS/MS). ... ...

Fragmentation of phosphorylated peptide ions via interaction with electronically excited metastable argon atoms was studied in a linear trap � time-of-flight mass spectrometer. Doubly charged ions of phosphorylated peptides from an Enolase digest were produced by electrospray ionization and subjected to a metastable atom beam in the ...

... characteristics � Enzyme digestion and peptide identification � Matrix-Assisted Laser Desorption and Ionization Time-of-Flight Mas...

... Title : Characterization of Aggregation in Alzheimer Beta-Protein Using Synthetic Peptide Fragments on Reverse-Phase Matrix,. ...

Two restriction fragments from corynebacteriophage beta vir tox+ that encode peptides similar to diphtheria toxin fragment A and the chain termination fragment, CRM45, have been cloned into Escherichia coli in plasmid pBR322. Clones containing the recombinant plasmids produced gene products that were active in ...

backbone, revealing the amino-acid sequence of the peptide. With sufficient peptide backbone fragments cleaved), adjacent amino-acids, peptide charge state, etc. While these techniques show promise, they haveAtlas project. Nucleic Acids Res 34, D655�8. 26 #12;Eddy, S. R. 1998. Profile hidden markov models. ...

The model amyloid peptide AAKLVFF was expressed as a His-tagged fusion protein with the immunoglobulin-binding domain B1 of streptococcal protein G (GB1), a small (56 residues), stable, single-domain protein. It is shown that expression of this model amyloid peptide is possible and is not hindered by aggregation. Formylation side reactions during the CNBr ...

The question of site of protonation in peptides that do not contain basic residues is addressed. The additional basicity of the peptide conferred by the amino terminus is removed by N-acetylation. Comparison of the surface-induced dissociation energy requirements for the fragmentation of the peptides with and ...

[reaction: see text] Solid-phase Staudinger ligation of small peptides was performed on a novel core-shell-type resin. Solid-phase Staudinger ligation was mediated by synthetic solid-supported phosphinothiol, which was readily prepared by a straightforward synthetic route. This protocol afforded final peptide products in excellent yields and purities and ...

Electron capture dissociation (ECD) of model peptides adducted with first row divalent transition metal ions, including Mn(2+), Fe(2+), Co(2+), Ni(2+), Cu(2+), and Zn(2+), were investigated. Model peptides with general sequence of ZGGGXGGGZ were used as probes to unveil the ECD mechanism of metalated peptides, where X is either V or W; ...

An improved method for de novo sequencing of arginine-containing peptides modified with succinimidyloxycarbonylmethyl tris(2,4,6-trimethoxyphenyl)phosphonium bromide (TMPP-Ac-OSu) is reported. A tagging reagent, TMPP-Ac-OSu, was introduced to improve the sequence analysis of peptides owing to the simplified fragmentation pattern. ...

We used surface-enhanced Raman scattering (SERS) to characterize the adsorption behavior of bombesin (BN) and five BN-related peptides, including phyllolitorin, [Leu(8)]phyllolitorin, neuromedin C (NMC), neuromedin B (NMB), and PG-L (Pseudophryne guntheri), in a silver colloidal solution. Our experiments show that the pyrrole coring of the Trp and aromatic ring of Phe of these ...

We investigate the charge-state selective cleavage in gas-phase protonated peptides by using electrospray ionization (ESI) Fourier-transform ion cyclotron resonance (FTICR) mass spectrometer (MS). The singly and multiply protonated peptides (Angiotensin II, Angiotensin I, Urotensin II, Bradykinin, Substance P) at the selected charge state were cleaved with ...

Angiogenesis is a crucial step in many pathologies, including tumor growth and metastasis. Here, we show that tilted peptides exert antiangiogenic activity. Tilted (or oblique-oriented) peptides are short peptides known to destabilize membranes and lipid cores and characterized by an asymmetric distribution of hydrophobic residues ...

A 14-residue fragment from near the C-terminus of the enzyme acetylcholinesterase (AChE) is believed to have a neurotoxic/neurotrophic effect acting via an unknown pathway. While the peptide is ?-helical in the full-length enzyme, the structure and association mechanism of the fragment are unknown. Using multiple molecular dynamics ...

Electrospray ionization (ESI) is considered a soft ionization method, and typically no peptide ion fragmentation is observed. Recently, it has been observed that intensive fragmentation of peptide ions can occur during nanoelectrospray (nanoESI) at special conditions, such as solutions containing high ...

The influence of charge state on the peptide dissociation behavior in tandem mass spectrometry (MS/MS) is worthy of discussion. Comparative studies of singly- and doubly-protonated peptide molecules are performed to explore the effect and mechanism of charge state on peptide fragmentation. In view of the ...

Despite the increasing number of studies using mass spectrometry for three dimensional analyses of proteins (MS3D), the identification of cross-linked peptides remains a bottleneck of the method. One of the main reasons for this is the lack of knowledge about the fragmentation of these species. Intermolecular cross-linked peptides are ...

BackgroundProtein identification using mass spectrometry is an important tool in many areas of the life sciences, and in proteomics research in particular. Increasing the number of proteins correctly identified is dependent on the ability to include new knowledge about the mass spectrometry fragmentation process, into computational algorithms designed to separate true matches ...

Photofragmentation of protonated dipeptides by 263 nm photons is investigated with an experimental technique based on the detection in coincidence of the ionic and neutral fragments. With this method, it is possible to determine whether the fragmentation takes place in one or several steps. The timing of these steps can also be evaluated. The ...

Data mining was performed on 28 330 unique peptide tandem mass spectra for which sequences were assigned with high confidence. By dividing the spectra into different sets based on structural features and charge states of the corresponding peptides, chemical interactions involved in promoting specific cleavage patterns in gas-phase ...

Electron capture dissociation (ECD), which provides more extensive sequence coverage compared to "slow heating" tandem mass spectrometric techniques such as collision-activated dissociation, constitutes a promising method for de novo sequencing of peptides and proteins. We have previously examined and characterized the ECD fragmentation behavior of small ...

High-density lipoproteins (HDL) were examined as potential carriers of small peptides in plasma. HDL purified by density gradient centrifugation was delipidated and fractionated by size-exclusion chromatography under denaturing conditions. By hplc and mass spectrometry, more than 100 peptide components were found in the size range from 1,000 to 5,000 Da. ...

In the current study the isolation and identification of Physcomitrella patens (Hedw.) B.S.G. moss peptides are described. Physcomitrella patens moss is actively used in recent years as a model organism to study the biology of plants. Protoplasts, protonemata and gametophores of the moss are demonstrated for the first time to contain diverse small ...

We describe methods for mass spectrometric identification of heme-containing peptides from digests of c-type cytochromes that contain the CXXCH(X = any amino acid) sequence motif. Analysis of purified standard heme-containing peptides showed that the charged heme group was present both before and after peptide ...

The production of toxic ergopeptine alkaloids by the fungi Claviceps purpurea and Neotyphodium coenophialum involves the activity of one or more nonribosomal peptide synthetases. Claviceps purpurea and N. coenophialum each have several different peptide synthetase genes, fragments of which have been cloned previously. An additional ...

A variety of additional factors that influence the in-source fragmentation of MALDI ionized peptides have been studied. In an attempt to further understand this in-source fragmentation process, instrumental parameters such as the desorption laser pulse width and wavelength, and ion-extraction delay period have been examined as to their ...

Molecular conformation of a peptide fragment of transthyretin in an amyloid fibril Christopher P�115 of tran- sthyretin, TTR(105�115), previously shown to form amyloid fibrils in vitro, has been determined and 15N-13C-13C chemical shift correlation experiments, performed on three fibril samples uniformly 13C

We report that degradation of proteins microinjected into human fibroblasts is accompanied by release into the culture medium of peptide fragments and intact proteins as well as single amino acids. For the nine proteins and polypeptides microinjected, acid-precipitable radioactivity, i.e. peptide fragments and/or ...

In this work, we studied the interactions of enzymes with model substrate surfaces using label-free techniques. Our model system was based on serine proteases (a class of enzymes that digests proteins) and surface-bound polypeptide substrates. While previous studies have focused on bulk media factors such as pH, ionic strength, and surfactants, this study focuses on the role of the surface-bound ...

Peptides are identified from a list of candidates using collision-induced dissociation tandem mass spectrometry data. A probabilistic model for the occurrence of spectral peaks corresponding to frequently observed partial peptide fragment ions is applied. As part of the identification procedure, a probability score is produced that ...

Identification, isolation and partial sequencing of a cell density protein produced by fibroblastic cells. The cell density signal protein comprising a 14 amino acid peptide or a fragment, variant, mutant or analog thereof, the deduced cDNA sequence from the 14 amino acid peptide, a recombinant protein, protein and ...

The fragmentation pathways of protonated peptides are reviewed in the present paper paying special attention to classification of the known fragmentation channels into a simple hierarchy defined according to the chemistry involved. It is shown that the 'mobile proton' model of peptide ...

In-source photocatalytic redox reactions based on a photosensitive target plate have been developed to realize peptide fragmentation during laser desorption ionization. Sample peptides and glucose are simply deposited on a spot of sintered TiO2 nanoparticles. With the irradiation of UV laser on TiO2, electrons are excited from the ...

Fragmentation pathways of peptide radical cations, M+, with well-defined initial location of the radical site were explored using collision-induced dissociation (CID) experiments. Peptide radical cations were produced by gas-phase fragmentation of CoIII(salen)-peptide complexes [salen = ...

Quantitative proteomics has become an important method in modern life sciences. Besides protein identification, the aspect of quantification is of rapidly increasing relevance. MeCAT (metal-coded affinity tagging) is able to provide a tool that enables relative as well as absolute quantification. For structural elucidation, knowledge on the fragmentation behavior of ...

Negative ion electrospray mass spectra of the peptides produced by tryptic and chymotrypsin digests of bovine insulin, and from the tryptic digest of lysozyme identify at least 80% of the sequences of these proteins. In particular, negative ion mass spectrometry identifies and positions disulfide moieties, and is the method of choice for identifying this post-translational ...

We have found that canine and rat hepatocytes convert (125I)iodoTyr10-glucagon to a peptide metabolite lacking the NH2-terminal three residues of the hormone. The peptide is released into the cell incubation medium and its formation is unaffected by a variety of lysosomotropic or other agents. Use of specific radioimmunoassays and gel filtration ...

This tutorial article introduces mass spectrometry (MS) for peptide fragmentation and protein identification. The current approaches being used for protein identification include top-down and bottom-up sequencing. Top-down sequencing, a relatively new approach that involves fragmenting intact proteins directly, is briefly introduced. ...

A key factor in the development of Type II diabetes is the loss of insulin producing pancreatic ?-cells. The amyloidogenic human Islet Amyloid Polypeptide (hIAPP also known as human amylin) is believed to play a crucial role in this biological process. Previous studies have shown that hIAPP forms small aggregates that kill ?-cells by disrupting the cellular membrane. In this study, we report ...

We report on the effectiveness of CID, HCD, and ETD for LC-FT MS/MS analysis of peptides using a tandem linear ion trap-Orbitrap mass spectrometer. A range of software tools and analysis parameters were employed to explore the use of CID, HCD, and ETD to identify peptides isolated from human blood plasma without the use of specific "enzyme rules". In the ...

Accurate modeling of peptide fragmentation is necessary for the development of robust scoring functions for peptide-spectrum matches, which are the cornerstone of MS/MS-based identification algorithms. Unfortunately, peptide fragmentation is a complex process that can involve several competing ...

Psalmopeotoxin I (PcFK1) is a 33-residue peptide isolated from the venom of the tarantula Psalmopoeus cambridgei. This peptide specifically inhibits the intra-erythrocyte stage of Plasmodium falciparum in vitro. It contains six cysteine residues forming three disulfide bridges and belongs to the superfamily of natural peptides ...

Peptides corresponding to sections 122-133, 136-147, and 154-164 of the heavy chain of the hemagglutinin of influenza virus A/Aichi/2/68 (H/sub 3/N/sub 2/) have been synthesized. The synthesis was performed by the stepwise growth of the peptide chain by means of activated esters of Boc-amino acids and the condensation of peptide blocks ...

While CART peptides have been implicated as novel, putative peptide neurotransmitters/cotransmitters, behavioral effects of these peptides have not yet been demonstrated. In this study, we show the first behavioral effect of CART peptides. I.c.v. administration of CART peptide ...

The beta bind: Copper(I) binds to amyloid {beta}-peptide fragments (see structure) as a stable bis(histidine), two-coordinate, near-linear complex, even in the presence of potential additional ligands. As has been proposed or assumed in other studies, the copper(I)-peptide complexes react with dioxygen to form the reactive oxygen ...

This invention relates to methods of preventing or reducing the severity of diabetes. In one embodiment, the method involves administering to the individual a peptide having substantially the sequence of a on-conserved region sequence of a T cell receptor present on the surface of T cells mediating diabetes or a fragment thereof, wherein the ...

We have developed a novel technique to separate and detect peptide fragments which are digested on the same column. In this procedure, pepsin is used to digest low femtomole amounts of [beta]-lactoglobulin on the column. Then, CZE and LINF are applied to separate and detect the peptide fragments. The advantages of ...

In two recent reports (D. L. Crimmins, J. Gorka, R. S. Thoma, and B. D. Schwartz (1988) J. Chromatogr. 443, 63-71; A. J. Alpert and P. C. Andrews (1988) J. Chromatogr. 443, 85-96) a sulfoethyl aspartamide column was shown to efficiently analyze peptides less than 25 residues in length which differ in the number of nominal positive charges at pH 3.0. In particular, the elution ...

Cockroaches have been recognized as a major cause of asthma. Bla g 4 is one of the most important German cockroach allergens. The aim of this study is to investigate IgE reactivity to the recombinant Bla g 4 (rBla g 4) in the sera of allergic patients and identify linear IgE binding epitope. For protein expression, full-length Bla g 4 (EF202172) was divided into 5 overlapping ...

Five peptides with antimicrobial activity were isolated from norepinephrine-stimulated skin secretions of the tetraploid frog Xenopus clivii Peracca, 1898 (Pipidae). Characterization of the peptides demonstrated that they are structurally similar to magainins (2 peptides), caerulein-precursor fragments, CPF (2 ...

The low resolution three-dimensional structure of a protein can be inferred from existing disulfide bridges or experimentally introduced chemical crosslinks. The general procedure involves enzymatic digestion of a protein followed by mass spectrometry-based identification of covalently-linked peptides, native disulfide-linked peptides and chemically ...

A novel peptide derivatization strategy based on guanidination and amidination is presented. Mass-coded labels help distinguish N- and C-terminal fragment ions produced by collision-induced dissociation and are of general utility since peptide N-termini are coded. The amidine labels also promote specific ...

The heterogeneity of crystalline bovine (ox)/porcine glucagon has been examined by gel filtration and ion-exchange chromatography. A strongly basic peptide that reacted well with antibodies to bovine/porcine glucagon was isolated and its primary structure was determined. The amino-acid sequence of the NH₂-terminal 29 residues of the 4500-dalton ...

This paper describes the results of an investigation to show that biosynthesis of POMC, its proteolytic processing, an secretion of the peptide products of that processing take place in the bovine adrenals. Rabbit antisera against endorphins were obtained and used for radioimmunoassay of peptides. I 125-labeled peptides were obtained ...

The X-ray structure of the Fab fragment from the anti-c-myc antibody 9E10 was determined both as complex with its epitope peptide and for the free Fab. In the complex, two Fab molecules adopt an unusual head to head orientation with the epitope peptide arranged between them. In contrast, the free Fab forms a dimer with different ...

Photodissociation with 157 nm light was implemented in an ABI model 4700 matrix-assisted laser desorption ionization (MALDI) tandem time-of-flight (TOF) mass spectrometer for peptide analysis. With a homemade computer program to control the light timing based on the m/z of each precursor ion, the photodissociation setup was seamlessly automated with the mass spectrometer. ...

Visible (458-514.5 nm) and uv (333-385 nm) photodissociation of the (M + H){sup +} ions of dinitrophenyl (DNP) derivatized amino acids and peptides is reported. Photoexcitation of the DNP peptides by a visible proton results in fragmentation of the peptide chain with little fragmentation within ...

This tutorial provides an overview of the evolution of some of the key concepts in the gas-phase fragmentation of different classes of peptide ions under various conditions [e.g. collision-induced dissociation (CID) and electron transfer dissociation (ETD)], and then demonstrates how these concepts can be used to develop new methods. For example, an ...

Although peptides have been used in biochemistry and pharmacology, their understanding has generally been limited to the functional fragment of proteins. Recent advances in peptides' solid phase synthesis technology, however, have increased the researcher...

The present invention relates to the structure of Fab 4E10, e.g., as a complex with herein identified peptide KGND, herein identified as a 4E10 mimetope on gp41, as determined by crystallographic techniques, and the confirmation that peptide KGND has a fu...

Micelle-Like Architecture of the Monomer Ensemble of Alzheimer's Amyloid- Peptide in Aqueous Aggregation of amyloid- (A) peptide, a 39- to 43-residue fragment of the amyloid precursor protein experimental studies have tried to characterize the atomic details of amyloid fibrils, which are the final

-associated Ii peptides; LIP, leupeptin-induced peptides. IiNmut, the Ii protein in which asparagine cleft. EXPERIMENTAL PROCEDURES Biochemicals and Antibodies--In 1 is a rat mAb directed against the N truncated Ii fragment LIP (leupeptin-induced peptide), have not yet been identified. There is some evidence

Previously we have shown that the presence of 3-nitrotyrosine within a peptide sequence severely depletes the peptide backbone fragments typically observed following electron capture dissociation (ECD) mass spectrometry. Instead, ECD of nitrated peptides is characterised by abundant losses of small neutrals ...

A method has been developed for de novo peptide sequencing using matrix-assisted laser desorption ionization mass spectrometry. This method will facilitate biological studies that require rapid determination of peptide or protein sequences, e.g., determination of posttranslational modifications, identification of active compounds isolated from ...

A method has been developed for de novo peptide sequencing using matrix-assisted laser desorption ionization mass spectrometry. This method will facilitate biological studies that require rapid determination of peptide or protein sequences, e.g., determination of posttranslational modifications, identification of active compounds isolated from ...

While collisionally activated dissociation (CAD) pathways for peptides are well characterized, those of intact proteins are not. We systematically assigned CAD product ions of ubiquitin, myoglobin, and bovine serum albumin generated using high-yield, in-source fragmentation. Assignment of >98% of hundreds of product ions implies ...

Here, we explore a de novo sequencing strategy in which we combine Lys-N protein digestion with differential isotopic dimethyl labeling to facilitate the (de novo) identification of multiply charged peptides in ESI-MS, both under CID and ETD conditions. For a large fraction of the Lys-N generated peptides, all primary amines are present at the N-terminal ...

1 Fragments of the N terminal part of adrenocorticotrophic hormone (ACTH) inhibited the electrically evoked contractions of the mouse vas deferens. This inhibition could be antagonized by naloxone. 2 The same fragments displaced radiolabelled morphine from morphine antiserum. 3 Structure-activity relationship studies showed that in both assay systems the ...

Post-translational modifications (PTM) corresponding to a gain in mass of 42 Da are of increasing interest. It has been widely recognized that acetylation and trimethylation on Lys regulates gene transcription and silencing. In addition, it was recently discovered that acetylation of Ser and Thr residues on a signaling kinase can block its activation. In this paper, three series of model ...

Protein disulfide isomerase (PDI) has been identified in a protein extract from the venom duct of the marine snail C. amadis. In-gel tryptic digestion of a thick protein band at approximately 55 kDa yields a mixture of peptides. Analysis of tryptic fragments by MALDI-MS/MS and LC-ESI-MS/MS methods permits sequence assignment. Three tryptic ...

Identification of phosphorylation sites is of interest due to their importance in protein regulation; however, the identification of the exact sites of this modification is not always easily obtained due to the dynamic nature of phosphorylation and the challenges faced during mass spectrometric analysis. Herein we elaborate on our previous communication (Diedrich, J. K.; Julian, R. R. J. Am. Chem. ...

Charge-directed fragmentation has been shown to be the prevalent dissociation step for protonated peptides under the low-energy activation (eV) regime. Thus, the determination of the ion structure and, in particular, the characterization of the protonation site(s) of peptides and their fragments is a key approach ...

The fragmentation reactions of deprotonated peptides containing aspartic acid have been elucidated using MS2 and MS3 experiments and accurate mass measurements where necessary. The disposition of labile (N and O bonded) hydrogens in the fragmentation products has been studied by exchanging the labile hydrogens for deuterium whereby the ...

Hemoglobin-based oxygen carriers (HBOCs) of bovine hemoglobin (Hb) or human Hb origin were developed for replacement or augmentation of blood during transfusion and have the potential to increase oxygen-carrying capacity of circulating blood and thus improve tissue oxygen delivery. Due to their potential for increasing oxygen-carrying capacity of circulating blood, they are excellent candidates ...

A new screening procedure is described that uses docking calculations to design enhanced agonist peptides that bind to major histocompatibility complex (MHC) class I receptors. The screening process proceeds via single mutations of one amino acid at the positions that directly interact with the MHC receptor. The energetic and structural effects of these mutations have been ...