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At least 1,495 records · Page 83Linked to original sources
PubMed1992

Comparison of the X-ray structure of native rubredoxin from Pyrococcus furiosus with the NMR structure of the zinc-substituted protein.

The three-dimensional X-ray structures of the oxidized and reduced forms of rubredoxin from Pyrococcus furiosus, determined at -161 degrees C, and the NMR structure of the zinc-substituted protein, determined in solution at 45 degrees C, are compared. The NMR and X-ray structures, which were determined independently, are very similar and lead to similar conclusions regarding the interactions that confer hyperthermostability.

Amino Acid Sequence↗
PubMed2003

Proposed amino acid sequence and the 1.63 A X-ray crystal structure of a plant cysteine protease, ervatamin B: some insights into the structural basis of its stability and substrate specificity.

The crystal structure of a cysteine protease ervatamin B, isolated from the medicinal plant Ervatamia coronaria, has been determined at 1.63 A. The unknown primary structure of the enzyme could also be traced from the high-quality electron density map. The final refined model, consisting of 215 amino acid residues, 208 water molecules, and a thiosulfate ligand molecule, has a crystallographic R-factor of 15.9% and a free R-factor of 18.2% for F > 2sigma(F). The protein belongs to the papain superfamily of cysteine proteases and has some unique properties compared to other members of the family. Though the overall fold of the structure, comprising two domains, is similar to the others, a few natural substitutions of conserved amino acid residues at the interdomain cleft of ervatamin B are expected to increase the stability of the protein. The substitution of a lysine residue by an arginine (residue 177) in this region of the protein may be important, because Lys --> Arg substitution is reported to increase the stability of proteins. Another substitution in this cleft region that helps to hold the domains together through hydrogen bonds is Ser36, replacing a conserved glycine residue in the others. There are also some substitutions in and around the active site cleft. Residues Tyr67, Pro68, Val157, and Ser205 in papain are replaced by Trp67, Met68, Gln156, and Leu208, respectively, in ervatamin B, which reduces the volume of the S2 subsite to almost one-fourth that of papain, and this in turn alters the substrate specificity of the enzyme.

Amino Acid Sequence↗
PubMed2001

Crystal structures of the peanut lectin-lactose complex at acidic pH: retention of unusual quaternary structure, empty and carbohydrate bound combining sites, molecular mimicry and crystal packing directed by interactions at the combining site.

The crystal structures of a monoclinic and a triclinic form of the peanut lectin-lactose complex, grown at pH 4.6, have been determined. They contain two and one crystallographically independent tetramers, respectively. The unusual "open" quaternary structure of the lectin, observed in the orthorhombic complex grown in neutral pH, is retained at the acidic pH. The sugar molecule is bound to three of the eight subunits in the monoclinic crystals, whereas the combining sites in four are empty. The lectin-sugar interactions are almost the same at neutral and acidic pH. A comparison of the sugar-bound and free subunits indicates that the geometry of the combining site is relatively unaffected by ligand binding. The combining site of the eighth subunit in the monoclinic crystals is bound to a peptide stretch in a loop from a neighboring molecule. The same interaction exists in two subunits of the triclinic crystals, whereas density corresponding to sugar exists in the combining sites of the other two subunits. Solution studies show that oligopeptides with sequences corresponding to that in the loop bind to the lectin at acidic pH, but only with reduced affinity at neutral pH. The reverse is the case with the binding of lactose to the lectin. A comparison of the neutral and acidic pH crystal structures indicates that the molecular packing in the latter is directed to a substantial extent by the increased affinity of the peptide loop to the combining site at acidic pH.

Carbohydrates↗
PubMed2006

Multiple mapping method: a novel approach to the sequence-to-structure alignment problem in comparative protein structure modeling.

A major bottleneck in comparative protein structure modeling is the quality of input alignment between the target sequence and the template structure. A number of alignment methods are available, but none of these techniques produce consistently good solutions for all cases. Alignments produced by alternative methods may be superior in certain segments but inferior in others when compared to each other; therefore, an accurate solution often requires an optimal combination of them. To address this problem, we have developed a new approach, Multiple Mapping Method (MMM). The algorithm first identifies the alternatively aligned regions from a set of input alignments. These alternatively aligned segments are scored using a composite scoring function, which determines their fitness within the structural environment of the template. The best scoring regions from a set of alternative segments are combined with the core part of the alignments to produce the final MMM alignment. The algorithm was tested on a dataset of 1400 protein pairs using 11 combinations of two to four alignment methods. In all cases MMM showed statistically significant improvement by reducing alignment errors in the range of 3 to 17%. MMM also compared favorably over two alignment meta-servers. The algorithm is computationally efficient; therefore, it is a suitable tool for genome scale modeling studies.

Algorithms↗
PubMed2006

SSALN: an alignment algorithm using structure-dependent substitution matrices and gap penalties learned from structurally aligned protein pairs.

In template-based modeling of protein structures, the generation of the alignment between the target and the template is a critical step that significantly affects the accuracy of the final model. This paper proposes an alignment algorithm SSALN that learns substitution matrices and position-specific gap penalties from a database of structurally aligned protein pairs. In addition to the amino acid sequence information, secondary structure and solvent accessibility information of a position are used to derive substitution scores and position-specific gap penalties. In a test set of CASP5 targets, SSALN outperforms sequence alignment methods such as a Smith-Waterman algorithm with BLOSUM50 and PSI_BLAST. SSALN also generates better alignments than PSI_BLAST in the CASP6 test set. LOOPP server prediction based on an SSALN alignment is ranked the best for target T0280_1 in CASP6. SSALN is also compared with several threading methods and sequence alignment methods on the ProSup benchmark. SSALN has the highest alignment accuracy among the methods compared. On the Fischer's benchmark, SSALN performs better than CLUSTALW and GenTHREADER, and generates more alignments with accuracy >50%, >60% or >70% than FUGUE, but fewer alignments with accuracy >80% than FUGUE. All the supplemental materials can be found at http://www.cs.cornell.edu/ approximately jianq/research.htm.

Algorithms↗
PubMed2007

Structural analysis and prediction of protein mutant stability using distance and torsion potentials: role of secondary structure and solvent accessibility.

Analyzing the factors behind protein stability is a key research topic in molecular biology, and has direct implications on protein structure prediction and protein-protein interactions. We have analyzed protein stability upon point mutations using a distance-dependant pair potential representing mainly through-space interactions, and torsion angle potential representing mainly neighboring effects as a basic statistical mechanical setup for the analysis. The synergetic effect of accessible surface area and secondary structure preferences was used as a classifier for the potentials. In addition, short-, medium-, and long-range interactions of the protein environment were also analyzed. Two datasets of point mutations were taken for the comparison of theoretically predicted stabilizing energy values with experimental DeltaDeltaG and DeltaDeltaGH(2)O from thermal and chemical denaturation experiments. These include 1538 and 1603 mutations, respectively, and contain 101 proteins that share a wide range of sequence identity. The resulting force fields were carefully evaluated with different statistical tests. Results show a maximum correlation of 0.87 with a standard error of 0.71 kcal/mol between predicted and measured DeltaDeltaG values and a prediction accuracy of 85.3% (stabilizing or destabilizing) for all mutations together. A correlation of 0.77 (more than 80% prediction accuracy with a standard error of 0.95 kcal/mol) each for the test dataset of split-sample validation and fivefold crossvalidation was obtained and a correlation of 0.70 (77.4% prediction accuracy with a standard error of 1.17 kcal/mol) was shown by the jackknife test. The same model was implemented, and the results were analyzed for mutations with DeltaDeltaGH(2)O. A correlation of 0.78 (standard error 0.96 kcal/mol) was observed with a prediction efficiency of 84.65%. This model can be used for the future prediction of protein structural stability together with various experimental techniques.

Databases, Protein↗
PubMed1991

1.59 A structure of trypsin at 120 K: comparison of low temperature and room temperature structures.

The structure of a rat trypsin mutant [S195C] at a temperature of 120 K has been refined to a crystallographic R factor of 17.4% between 12.0 and 1.59 A and is compared with the structure of the D102N mutant at 295 K. A reduction in the unit cell dimensions in going from room temperature to low temperature is accompanied by a decrease in molecular surface area and radius of gyration. The overall structure remains similar to that at room temperature. The attainable resolution appears to be improved due to the decrease in the fall off of intensities with resolution [reduction of the temperature factor]. This decreases the uncertainty in the atomic positions and allows the localization of more protein atoms and solvent molecules in the low temperature map. The largest differences between the two models occur at residues with higher than average temperature factors. Several features can be localized in the solvent region of the 120 K map that are not seen in the 295 K map. These include several more water molecules as well as an interstitial sulfate ion and two interstitial benzamidine molecules.

Animals↗
PubMed1994

Rhodopsin's secondary structure revisited: assignment of structural elements.

FT-IR spectroscopy has been applied to study the secondary structure of rhodopsin in dehydrated films of bovine rod photoreceptor membranes. Curve fitting analysis of the amide I band around 1658 cm-1 compares well with data obtained from samples in the hydrated state. Repeating this analysis on samples, treated with proteinase K or thermolysin, secondary structural elements at the cytoplasmic side of the photoreceptor membrane can be located. We present evidence for the location of a beta-sheet and a beta-turn near the lipid anchor in the C-terminal region of the protein, and for an alpha-helical structure in the third cytoplasmic loop.

Endopeptidase K↗
PubMed1994

The secondary structure of the von Willebrand factor type A domain in factor B of human complement by Fourier transform infrared spectroscopy. Its occurrence in collagen types VI, VII, XII and XIV, the integrins and other proteins by averaged structure predictions.

The type A domain of the von Willebrand Factor is found also in the complement proteins factor B (FB), C2, CR3 and CR4, the integrins, collagen types VI, VII, XII and XIV, and other proteins. FB is a component of the alternative pathway of the complement system of immune defence, and is cleaved into the fragments Bb and Ba during complement activation. Bb contains a von Willebrand Factor type A (vWF) domain of unknown secondary structure and a serine proteinase (SP) domain, whereas Ba contains three short consensus repeat/complement control protein (SCR/CCP) domains. Fourier transform infrared (FT-IR) spectroscopy on a recombinant vWF domain and on FB and its Bb and Ba fragments shows a broad amide I band. In H2O buffer, second derivative spectra of the amide I band show subcomponents at 1654 to 1657 cm-1, which is typical of alpha-helix, and at 1676 to 1685 cm-1 and 1636 to 1637 cm-1, which are typical of beta-strand. alpha-Helix was detected in the vWF domain, the Bb fragment and FB, and the proportion of alpha-helix present decreased in that order. This shows that the vWF domain contains appreciable amounts of alpha-helix, while the SP and SCR/CCP domains are almost entirely beta-sheet in their secondary structures. Quantitative integration of the vWF FT-IR spectrum showed that this contained 31% alpha-helix and 36% beta-sheet. In 2H2O buffer, the alpha-helix content in the vWF domain is sensitive to the solvent, while the beta-sheet content is less so. An alignment of 75 vWF type A sequences from 25 proteins was used for averaged secondary structure predictions of the total length of 206 residues by the Robson and Chou-Fasman methods. In support of the FT-IR analysis, a total of at least five well-predicted alpha-helices (35% of residues) and at least five well-predicted beta-strands (21% of residues) were identified by both predictive methods, all of which were interspersed by regions of coil or turn conformations. Eight of the ten predicted alpha-helices and beta-strands form an alternating arrangement with each other. Since the predicted alpha-helices are mostly amphipathic, and since the alpha-helix FT-IR band is sensitive to solvent, the alpha-helices are inferred to be on the protein surface.(ABSTRACT TRUNCATED AT 400 WORDS)

Amino Acid Sequence↗
PubMed1998

Structural basis for the binding of an anti-cytochrome c antibody to its antigen: crystal structures of FabE8-cytochrome c complex to 1.8 A resolution and FabE8 to 2.26 A resolution.

A complete understanding of antibody-antigen association and specificity requires the stereochemical description of both antigen and antibody before and upon complex formation. The structural mechanism involved in the binding of the IgG1 monoclonal antibody E8 to its highly charged protein antigen horse cytochrome c (cyt c) is revealed by crystallographic structures of the antigen-binding fragment (Fab) of E8 bound to cyt c (FabE8-cytc), determined to 1.8 A resolution, and of uncomplexed Fab E8 (FabE8), determined to 2.26 A resolution. E8 antibody binds to three major discontiguous segments (33 to 39; 56 to 66; 96 to 104), and two minor sites on cyt c opposite to the exposed haem edge. Crystallographic definition of the E8 epitope complements and extends biochemical mapping and two-dimensional nuclear magnetic resonance with hydrogen-deuterium exchange studies. These combined results demonstrate that antibody-induced stabilization of secondary structural elements within the antigen can propagate locally to adjacent residues outside the epitope. Pre-existing shape complementarity at the FabE8-cytc interface is enhanced by 48 bound water molecules, and by local movements of up to 4.2 A for E8 antibody and 8.9 A for cyt c. Glu62, Asn103 and the C-terminal Glu104 of cyt c adjust to fit the pre-formed VL "hill" and VH "valley" shape of the grooved E8 paratope. All six E8 complementarity determining regions (CDRs) contact the antigen, with CDR L1 forming 46% of the total atomic contacts, and CDRs L1 (29%) and H3 (20%) contributing the highest percentage of the total surface area of E8 buried by cyt c (550 A2). The E8 antibody covers 534 A2 of the cyt c surface. The formation of five ion pairs between E8 and flexible cyt c residues Lys60, Glu62 and Glu104 suggests the importance of mobile regions and electrostatic interactions in providing the exquisite specificity needed for recognition of this extremely conserved protein antigen. The highly homologous VL domains of E8 and anti-lysozyme antibody D1. 3 achieve their distinct antigen-binding specificities by expanding the impact of their limited sequence differences through the recruitment of different sets of conserved residues and distinctly different CDR L3 conformations.

Animals↗
PubMed1999

X-ray structure determination of human profilin II: A comparative structural analysis of human profilins.

Human profilins are multifunctional, single-domain proteins which directly link the actin microfilament system to a variety of signalling pathways via two spatially distinct binding sites. Profilin binds to monomeric actin in a 1:1 complex, catalyzes the exchange of the actin-bound nucleotide and regulates actin filament barbed end assembly. Like SH3 domains, profilin has a surface-exposed aromatic patch which binds to proline-rich peptides. Various multidomain proteins including members of the Ena/VASP and formin families localize profilin:actin complexes through profilin:poly-L-proline interactions to particular cytoskeletal locations (e.g. focal adhesions, cleavage furrows). Humans express a basic (I) and an acidic (II) isoform of profilin which exhibit different affinities for peptides and proteins rich in proline residues. Here, we report the crystallization and X-ray structure determination of human profilin II to 2.2 A. This structure reveals an aromatic extension of the previously defined poly-L-proline binding site for profilin I. In contrast to serine 29 of profilin I, tyrosine 29 in profilin II is capable of forming an additional stacking interaction and a hydrogen bond with poly-L-proline which may account for the increased affinity of the second isoform for proline-rich peptides. Differential isoform specificity for proline-rich proteins may be attributed to the differences in charged and hydrophobic residues in and proximal to the poly-L-proline binding site. The actin-binding face remains nearly identical with the exception of five amino acid differences. These observations are important for the understanding of the functional and structural differences between these two classes of profilin isoforms.

Acids↗
PubMed2000

Structure and function of the mouse DNA methyltransferase gene: Dnmt1 shows a tripartite structure.

Dnmt1 is the predominant DNA methyltransferase (MTase) in mammals. The C-terminal domain of Dnmt1 clearly shares sequence similarity with many prokaryotic 5mC methyltransferases, and had been proposed to be sufficient for catalytic activity. We show here by deletion analysis that the C-terminal domain alone is not sufficient for methylating activity, but that a large part of the N-terminal domain is required in addition. Since this complex structure of Dnmt1 raises issues about its evolutionary origin, we have compared several eukaryotic MTases and have determined the genomic organization of the mouse Dnmt1 gene. The 5' most part of the N-terminal domain is dispensible for enzyme activity, includes the major nuclear import signal and comprises tissue-specific exons. Interestingly, the functional subdivision of Dnmt1 correlates well with the structure of the Dnmt1 gene in terms of intron/exon size distribution as well as sequence conservation. Our results, based on functional, structural and sequence comparison data, suggest that the gene has evolved from the fusion of at least three genes.

Amino Acid Motifs↗
PubMed2001

Molecular mimicry of host structures by lipooligosaccharides of Neisseria meningitidis: characterization of sialylated and nonsialylated lacto-N-neotetraose (Galbeta1-4GlcNAcbeta1-3Galbeta1-4Glc) structures in lipooligosaccharides using monoclonal antibodies and specific lectins.

Neisseria meningitidis lipooligosaccharides (LOSs) are classified into 12 immunotypes. Most LOSs are heterogeneous in having a few components by SDS-PAGE analysis that differ antigenically and chemically. We have utilized a monoclonal antibody that recognizes lacto-N-neotetraose (LNnT) and the lectin, Maackia amurensis leukoagglutinin (MAL), which is specific for NeuNAcalpha2-3Galbeta1-4GlcNAc trisacchride sequence to characterize the 12 N. meningitidis LOSs. Using the combination of ELISA, SDS-PAGE, Western blotting, and other chemical analyses, we have shown that the LNnT (Galbeta1-4GlcNAcbeta1-3Galbeta1-4Glc) sequence was present in the 4.0-kDa LOS components of seven immunotype LOSs seen on SDS-PAGE. Six of the seven LNnT-containing LOSs also bound the MAL lectin indicating that N-acetylneuraminic acid (NeuNAc) was alpha2,3-linked to the LNnT sequence in the LOSs. Sialylation of the terminal Gal of LNnT-containing 4.0-kDa component caused only a slight increase in its apparent MW to 4100 on SDS-PAGE. The one LOS with the LNnT-containing component, but not MAL-binding, was from a Group A N. meningitidis, which does not synthesize CMP-NeuNAc, the substrate needed for LOS sialylation. Thus, it is concluded (1) a common LNnT sequence is present in seven immunotype LOSs in addition to their immunotype epitopes, and (2) NeuNAc is alpha2 --> 3 linked to the terminal Gal of LNnT if a organism synthesizes CMP-NeuNAc such as Groups B and C organisms. The above conclusions are consistent with the published structures of N. meningitidis LOSs. The results also demonstrate that specific carbohydrate-binding lectins and monoclonal antibodies can be used as simple yet effective tools to characterize specific carbohydrate sequences in a bacterial LOS or LPS such as N. meningitidis LOS. It is intriguing that N. meningitidis LOSs mimic certain glycosphingolipids, such as paragloboside (LNnT-ceramide) and sialylparagloboside, and some glycoproteins of the host in having LNnT and N-acetyllactosamine sequences respectively with or without alpha2 --> 3 linked NeuNAc. Epidemiological studies of N. meningitidis suggest that the molecular mimicry of host structures by its LOS plays a role in the pathogenesis of N. meningitidis by helping the organism to evade host immune defenses in man. The molecular mimicry of host structures by LOS or LPS is also found in other human pathogens such as N. gonorrhoeae, Haemophilus ducreyi, H. influenaze, Moraxella catarrhalis, Campylobacter jejuni, and Helicobacter pylori.

Animals↗
PubMed1992

Crystal structure of alpha-dendrotoxin from the green mamba venom and its comparison with the structure of bovine pancreatic trypsin inhibitor.

The three-dimensional structure of alpha-dendrotoxin (alpha-DTX) from the green mamba (Dendroaspis angusticeps) venom has been determined crystallographically using the method of isomorphous replacement and refined at 2.2 A resolution using a restrained least-squares method. The crystallographic R-factor is 0.169 for all 3451 measured reflections between 7.0 and 2.2 A. Although the main-chain fold of alpha-DTX is similar to that of homologous bovine pancreatic trypsin inhibitor (BPTI), there are significant differences involving segments of the polypeptide chain close to the "antiprotease site" of BPTI. Comparison of the structure of alpha-DTX with the existing models of BPTI and its complexes with trypsin and kallikrein reveals structural differences that explain the inability of alpha-DTX to inhibit trypsin and chymotrypsin.

Amino Acid Sequence↗
PubMed1992

Roles of structural domains in the morphology and surface anchoring of the tetragonal paracrystalline array of Aeromonas hydrophila. Biochemical characterization of the major structural domain.

The tetragonally arranged S-layer of Aeromonas hydrophila contains two morphological domains. The mature S-layer protein of A. hydrophila has a subunit molecular weight of 52,000, and has been reported to contain two structural domains. Here a mutant has been isolated which produces an S-layer of subunit molecular weight 38,650 as determined by sedimentation analysis. This truncated S-protein was exported via the periplasm to the cell surface, but could not self-assemble into a tetragonal array or be anchored to the cell surface. Instead the truncated protein formed cup-like structures which were purified and characterized biochemically. Automated Edman degradation showed that the truncated protein comprised the amino-terminal structural domain of the S-protein. This domain had an increased hydrophobic amino acid content relative to the wild-type protein, and contained approximately 42% beta-sheet, 10% alpha-helix, and 19% beta-turn. Differences in alpha-helix and beta-turn contents between the wild-type and truncated proteins were observed when the effects of pH and SDS were examined, indicating that the carboxy terminus influences the effects of environmental change on the conformation of the S-protein. This lesser carboxy-terminal array also appears to be required for both correct array morphology, and array anchoring, while the greater amino-terminal domain appears to comprise the major morphological core of the surface array.

Aeromonas hydrophila↗
PubMed1995

Crystal structure and mutational analysis of human uracil-DNA glycosylase: structural basis for specificity and catalysis.

Crystal structures of the DNA repair enzyme human uracil-DNA glycosylase (UDG), combined with mutational analysis, reveal the structural basis for the specificity of the enzyme. Within the classic alpha/beta fold of UDG, sequence-conserved residues form a positively charged, active-site groove the width of duplex DNA, at the C-terminal edge of the central four-stranded parallel beta sheet. In the UDG-6-aminouracil complex, uracil binds at the base of the groove within a rigid preformed pocket that confers selectivity for uracil over other bases by shape complementary and by main chain and Asn-204 side chain hydrogen bonds. Main chain nitrogen atoms are positioned to stabilize the oxyanion intermediate generated by His-268 acting via nucleophilic attack or general base mechanisms. Specific binding of uracil flipped out from a DNA duplex provides a structural mechanism for damaged base recognition.

Amino Acid Sequence↗
PubMed1994

Structure-function correlates of autoantibodies to nucleic acids. Lessons from immunochemical, genetic and structural studies.

Nucleic acid binding autoantibodies are the hallmark of the human autoimmune disease, systemic lupus erythematosus (SLE) and are also prevalent in mouse models of this disease. The immunologic stimuli for the production of these antibodies as well as their pathogenic mechanisms are not well understood. However, extensive immunochemical and genetic studies, together with initial crystallographic analysis and computer modeling, have suggested several structure-function correlates which will form the basis for future research. The anti-DNA and anti-RNA autoantibodies comprise a continuous spectrum of specificities in which a delicate balance exists between the binding to the sugar-phosphate backbone and the interactions with the heterocyclic bases of the nucleic acid. Prominent in these interactions are the products of specific V-region immunoglobulin genes, some of which appear to be uniquely suitable for nucleic acid binding. Other structural elements encoded by D minigenes, N sequences and somatic mutations, help to increase the affinity of the binding interaction, and may also increase the repertoire of nucleic acid binding antibodies by combining with a relatively large number of additional V-gene products. Initial crystallographic analyses of anti-DNA antibodies indicate some fundamental differences in the structure and shape of ssDNA and dsDNA antibody combining sites. However, they also suggest a considerable degree of flexibility of both antibody and antigen, which is induced by their binding interaction.

Amino Acid Sequence↗
PubMed2004

Algorithm-assisted elucidation of disulfide structure: application of the negative signature mass algorithm to mass-mapping the disulfide structure of the 12-cysteine transforming growth factor beta type II receptor extracellular domain.

The power of an algorithm-driven method for interpreting disulfide mass-mapping data is demonstrated in the context of determining the disulfide structure of the extracellular domain of the transforming growth factor beta type II receptor, a 14-kDa cystinyl protein containing 12 cysteines in the form of six disulfide bonds. The disulfide mass-mapping methodology is based on partial reduction and cyanylation-induced cleavage of the cystinyl protein. Because the multiplicity of possible disulfide structures that must be considered grows rapidly with the number of cysteines, as does the difficulty in physically isolating each of the partially reduced and cyanylated isoforms of the analyte, manual data interpretation for disulfide mapping a cystinyl protein containing more than eight cysteines becomes unmanageable. Recently, we introduced the concept of a "negative signature mass algorithm" (NSMA) to determine the disulfide structure of a cystinyl protein by processing an input of its amino acid sequence and mass spectral data from analysis of its associated cyanylation-induced cleavage products. Here, we present experimental results to validate the NSMA concept. A key advantage of the NSMA, in addition to convenience and automation, is its capacity to interpret mass spectra from mixtures of cyanylation-induced cleavage fragments without separating the partially reduced isoforms of the cystinyl protein and without knowledge of the extent of partial reduction.

Algorithms↗