Anticoagulant serine fibrinogenases from Vipera lebetinavenom: structure-function relationships

2003 ◽  
Vol 89 (05) ◽  
pp. 826-831 ◽  
Author(s):  
Anu Aaspõllu ◽  
Jüri Siigur ◽  
Ene Siigur

SummaryAmino acid sequences of two anticoagulant serine fibrinogenases – α- and β-fibrinogenase (VLAF and VLBF) from Vipera lebetina venom have been deduced from the cDNA sequences encoding the enzymes. The mature protein sequences of 234 amino acids (VLAF) and 233 amino acids (VLBF) exhibit significant similarity with other snake venom serine proteinases. Both enzymes contain the catalytic triad His57, Asp102, Ser195, and twelve conserved cysteines forming six disulfide bridges. Unlike typical trypsin-like serine proteinases, they lack the third aspartate, Asp189 which is replaced by Gly189. VLBF is a typical representative of arginine esterases – β-fibrinogenases. α-Fibrinogenase, VLAF, is unique among snake venom serine proteinases with homologous structure. Until now there is no evidence of the anticoagulant serine enzymes degrading fibrinogen α-chain only and lacking esterolytic activity.Parts of this paper were presented at the 17th International Fibrinogen Workshop of the International Fibrinogen Research Society (IFRS) held in Munich, Germany, September, 2002.The sequence data of Vipera lebetina mRNA for α- and β-fibrinogenase have been deposited in the GenBank database under accession numbers AF528193 (VLAF) and AF536235 (VLBF).

2018 ◽  
Author(s):  
Shou-Wen Wang ◽  
Anne-Florence Bitbol ◽  
Ned S. Wingreen

AbstractStatistical analysis of alignments of large numbers of protein sequences has revealed “sectors” of collectively coevolving amino acids in several protein families. Here, we show that selection acting on any functional property of a protein, represented by an additive trait, can give rise to such a sector. As an illustration of a selected trait, we consider the elastic energy of an important conformational change within an elastic network model, and we show that selection acting on this energy leads to correlations among residues. For this concrete example and more generally, we demonstrate that the main signature of functional sectors lies in the small-eigenvalue modes of the covariance matrix of the selected sequences. However, secondary signatures of these functional sectors also exist in the extensively-studied large-eigenvalue modes. Our simple, general model leads us to propose a principled method to identify functional sectors, along with the magnitudes of mutational effects, from sequence data. We further demonstrate the robustness of these functional sectors to various forms of selection, and the robustness of our approach to the identification of multiple selected traits.Author summaryProteins play crucial parts in all cellular processes, and their functions are encoded in their amino-acid sequences. Recently, statistical analyses of protein sequence alignments have demonstrated the existence of “sectors” of collectively correlated amino acids. What is the origin of these sectors? Here, we propose a simple underlying origin of protein sectors: they can arise from selection acting on any collective protein property. We find that the main signature of these functional sectors lies in the low-eigenvalue modes of the covariance matrix of the selected sequences. A better understanding of protein sectors will make it possible to discern collective protein properties directly from sequences, as well as to design new functional sequences, with far-reaching applications in synthetic biology.


Toxicon ◽  
2002 ◽  
Vol 40 (1) ◽  
pp. 51-54 ◽  
Author(s):  
Mari Samel ◽  
Juhan Subbi ◽  
Jüri Siigur ◽  
Ene Siigur

1999 ◽  
Vol 124 (3) ◽  
pp. 224-233 ◽  
Author(s):  
Ryutaro Tao ◽  
Hisayo Yamane ◽  
Akira Sugiura ◽  
Hideki Murayama ◽  
Hidenori Sassa ◽  
...  

This report identifies S-RNases of sweet cherry (Prunus avium L.) and presents information about cDNA sequences encoding the S-RNases, which leads to the development of a molecular typing system for S-alleles in this fruit tree species. Stylar proteins of sweet cherry were surveyed by two dimensional polyaclylamide gel electrophoresis (2D-PAGE) to identify S-proteins associated with gametophytic self-incompatibility. Glycoprotein spots linked to S-alleles were found in a group of proteins which had Mr and pI similar to those of other rosaceous S-RNases. These glycoproteins were present at highest concentration in the upper segment of the mature style and shared immunological characteristics and N-terminal sequences with those of S-RNases of other plant species. cDNAs encoding these glycoproteins were cloned based on the N-terminal sequences. Genomic DNA and RNA blot analyses and deduced amino acid sequences indicated that the cDNAs encode S-RNases; thus the S-proteins identified by 2D-PAGE are S-RNases. Although S1 to S6-alleles of sweet cherry cultivars could be distinguished from each other with the genomic DNA blot analysis, a much simpler method of PCR-based typing system was developed for the six S-alleles based on the DNA sequence data obtained from the cDNAs encoding S-RNases.


2004 ◽  
Vol 186 (21) ◽  
pp. 7243-7253 ◽  
Author(s):  
René Handrick ◽  
Simone Reinhardt ◽  
Philipp Kimmig ◽  
Dieter Jendrossek

ABSTRACT Rhodospirillum rubrum possesses a putative intracellular poly(3-hydroxybutyrate) (PHB) depolymerase system consisting of a soluble PHB depolymerase, a heat-stable activator, and a 3-hydroxybutyrate dimer hydrolase (J. M. Merrick and M. Doudoroff, J. Bacteriol. 88:60-71, 1964). In this study we reinvestigated the soluble R. rubrum PHB depolymerase (PhaZ1). It turned out that PhaZ1 is a novel type of PHB depolymerase with unique properties. Purified PhaZ1 was specific for amorphous short-chain-length polyhydroxyalkanoates (PHA) such as native PHB, artificial PHB, and oligomer esters of (R)-3-hydroxybutyrate with 3 or more 3-hydroxybutyrate units. Atactic PHB, (S)-3-hydroxybutyrate oligomers, medium-chain-length PHA, and lipase substrates (triolein, tributyrin) were not hydrolyzed. The PHB depolymerase structural gene (phaZ1) was cloned. Its deduced amino acid sequence (37,704 Da) had no significant similarity to those of intracellular PHB depolymerases of Wautersia eutropha or of other PHB-accumulating bacteria. PhaZ1 was found to have strong amino acid homology with type-II catalytic domains of extracellular PHB depolymerases, and Ser42, Asp138, and His178 were identified as catalytic-triad amino acids, with Ser42 as the putative active site. Surprisingly, the first 23 amino acids of the PHB depolymerase previously assumed to be intracellular revealed features of classical signal peptides, and Edman sequencing of purified PhaZ1 confirmed the functionality of the predicted cleavage site. Extracellular PHB depolymerase activity was absent, and analysis of cell fractions unequivocally showed that PhaZ1 is a periplasm-located enzyme. The previously assumed intracellular activator/depolymerase system is unlikely to have a physiological function in PHB mobilization in vivo. A second gene, encoding the putative true intracellular PHB depolymerase (PhaZ2), was identified in the genome sequence of R. rubrum.


2016 ◽  
Vol 14 (2) ◽  
pp. 327-336
Author(s):  
Le Dinh Hung ◽  
Makoto Hirayama ◽  
Kanji Hori

The red algae, Eucheuma denticulatum and Kappaphycus striatum have been widely cultivated in Vietnam as a source of carrageenophytes for industry. In the past, biochemical properties of lectins isolated from these algae has been characterized  and  evaluated extensively. However, gene coding for such lectins isn’t studied yet. In this study, their full length cDNA is amfplified using cDNA ends (RACE) methods. Sequence analysis revealed that cDNA of EDA-2 from E. denticulatum consisted of 1,158 bp containing 103 bp of a 5'untranslated region, 248 bp of 3'untranslated region, and 807 bp of an open reading frame; and cDNA of KSA-2 from K. striatum consisted of 1174 bp containing 94 bp of the 5'-untranslated region, 273 bp of 3'untranslated region and 807 bp of the open reading frame. The cDNA of both EDA-2 and KSA-2 encoded for a polypeptide of 269 amino acids including an initiating methionine, but differed in sequences and molecular masses. The deduced amino acid sequences of EDA-2 and KSA-2 composed of four tandem repeated domains with about 67 amino acids each. The primary structure of EDA-2 and KSA-2 is highly similar to those of the high mannose N-glycan specific lectins including OAA from cyanobacterium, BOA, MBHA and PFA from bacteria, and ESA-2, KAA-1, KAA-2 from macro red algae, which showed strong anti-HIV and anti-influenza virus activities. These results indicate that these cultivated algae are becoming promising materials for production of anti-virus reagent or functional food that can prevent virus infection in future.


1976 ◽  
Vol 157 (2) ◽  
pp. 449-459 ◽  
Author(s):  
J C Jaton

The amino acid sequence of the V (variable) region of the heavy (H) chain of rabbit antibody BS-1, raised against type III pneumococcal vaccine, is reported. Together with the sequence data of the V region of the light (L) chain previously determined [Jaton (1974a) Biochem. J. 141, 1-13], the present work completes the analysis of the V domain of the homogeneous antibody BS-1. The V domains (VL + VH regions) of this antibody are compared with those of two other anti-(type III) pneumococcal antibodies BS-5 and K-25 [Jaton (1975) Biochem. J. 147, 235-247]. Except for the second hypervariable section of the L chains, these antibodies have very different sequences in the hypervariable segments of the V domains. Within the third hypervariable region of the H chain, each antibody has a different length: BS-1 is three amino acids shorter than K-25 and two amino acids shorter than BS-5. When the sequences in that section are aligned for maximal homology, only two residues, glycine-97 and leucine-101, are common to the three antibodies. On the basis of the amino acid sequences of these three anti-pneumococcal antibodies, the results do not support the concept of a simple correlation between primary structure in the hypervariable sections (known to determine the shape of the combining site) and antigen-binding specificity.


1976 ◽  
Vol 159 (2) ◽  
pp. 335-345 ◽  
Author(s):  
J G Beeley

Tryptic glycopeptides were purified from the sialic acid-free variant of ovomucoid, O1, and its CNBr fragments. The amino acid sequences adjacent to the four major sites of carbohydrate (Carb.) attachment were: (1), Phe-Pro-Asn(Carb.)-Ala-Thr-Asp-Lys-Glu-Gly-Lys; (2), Ala-Try-Ser-Ile-Glu-Phe-Gly-Thr-Asn (Carb.)-Ile-Ser-Lys; (3), Glu, Thr-Val-Pro-Met-Asn(Carb.)-cys-Ser; (4), Ser-Ser-Tyr-Ala-Asn (Carb.)-Thr-Thr-Ser-Glu-Asp-Gly-Lys, Glycosylated Asn residues were located at position 10, between residues 49 and 60, and at positions 69 and 75, in the primary sequence. All of these carbohydrate groups contained GlcNAc, Man and Gal in the approximate molar proprotions 5:3:0.5. A further glycopeptide containing His was isolated in low yield, suggesting that some carbohydrate is attached at a fifth site. Two of the carbohydrate-attachment sites (Asn-10 and Asn-75) occur in sequences that show internal homologies. These are presumed to have evolved as a consequence of partial gene duplication. Three of the carbohydrate-attachment sites occur in similar positions to the carbohydrate groups in quail ovomucoid [Laskowski (1976) Protides Biol. Fluids Proc. Colloq. 23, in the press]. Prediction of peptide conformation from the sequence data by the method of Chou & Fasman [(1974) Biochemistry 13, 222-225] indicated that four glycosylated Asn residues in hen ovomucoid are very close to groups of amino acids that occur with high frequency in β-turns. The possible significance of peptide-chain conformation in the attachment of carbohydrate to glycoproteins is briefly discussed.


Genetics ◽  
1997 ◽  
Vol 145 (2) ◽  
pp. 297-309 ◽  
Author(s):  
Stuart J Newfeld ◽  
Richard W Padgett ◽  
Seth D Findley ◽  
Brent G Richter ◽  
Michele Sanicola ◽  
...  

Using an elaborate set of cis-regulatory sequences, the decapentaplegic (dpp) gene displays a dynamic pattern of gene expression during development. The C-terminal portion of the DPP protein is processed to generate a secreted signaling molecule belonging to the transforming growth factor-β (TGF-β) family. This signal, the DPP ligand, is able to influence the developmental fates of responsive cells in a concentration-dependent fashion. Here we examine the sequence level organization of a significant portion of the dpp locus in Drosophila melanogaster and use interspecific comparisons with D. simulans, D. pseudoobscura and D.virilis to explore the molecular evolution of the gene. Our interspecific analysis identified significant selective constraint on both the nucleotide and amino acid sequences. As expected, interspecific comparison of protein coding sequences shows that the C-terminal ligand region is highly conserved. However, the central portion of the protein is also conserved, while the N-terminal third is quite variable. Comparison of noncoding regions reveals significant stretches of nucleotide identity in the 3′ untranslated portion of exon 3 and in the intron between exons 2 and 3. An examination of cDNA sequences representing five classes of dpp transcripts indicates that these transcripts encode the same polypeptide.


Entropy ◽  
2021 ◽  
Vol 23 (5) ◽  
pp. 530
Author(s):  
Milton Silva ◽  
Diogo Pratas ◽  
Armando J. Pinho

Recently, the scientific community has witnessed a substantial increase in the generation of protein sequence data, triggering emergent challenges of increasing importance, namely efficient storage and improved data analysis. For both applications, data compression is a straightforward solution. However, in the literature, the number of specific protein sequence compressors is relatively low. Moreover, these specialized compressors marginally improve the compression ratio over the best general-purpose compressors. In this paper, we present AC2, a new lossless data compressor for protein (or amino acid) sequences. AC2 uses a neural network to mix experts with a stacked generalization approach and individual cache-hash memory models to the highest-context orders. Compared to the previous compressor (AC), we show gains of 2–9% and 6–7% in reference-free and reference-based modes, respectively. These gains come at the cost of three times slower computations. AC2 also improves memory usage against AC, with requirements about seven times lower, without being affected by the sequences’ input size. As an analysis application, we use AC2 to measure the similarity between each SARS-CoV-2 protein sequence with each viral protein sequence from the whole UniProt database. The results consistently show higher similarity to the pangolin coronavirus, followed by the bat and human coronaviruses, contributing with critical results to a current controversial subject. AC2 is available for free download under GPLv3 license.


2021 ◽  
Vol 22 (3) ◽  
pp. 1018
Author(s):  
Hiroaki Yokota

Helicases are nucleic acid-unwinding enzymes that are involved in the maintenance of genome integrity. Several parts of the amino acid sequences of helicases are very similar, and these quite well-conserved amino acid sequences are termed “helicase motifs”. Previous studies by X-ray crystallography and single-molecule measurements have suggested a common underlying mechanism for their function. These studies indicate the role of the helicase motifs in unwinding nucleic acids. In contrast, the sequence and length of the C-terminal amino acids of helicases are highly variable. In this paper, I review past and recent studies that proposed helicase mechanisms and studies that investigated the roles of the C-terminal amino acids on helicase and dimerization activities, primarily on the non-hexermeric Escherichia coli (E. coli) UvrD helicase. Then, I center on my recent study of single-molecule direct visualization of a UvrD mutant lacking the C-terminal 40 amino acids (UvrDΔ40C) used in studies proposing the monomer helicase model. The study demonstrated that multiple UvrDΔ40C molecules jointly participated in DNA unwinding, presumably by forming an oligomer. Thus, the single-molecule observation addressed how the C-terminal amino acids affect the number of helicases bound to DNA, oligomerization, and unwinding activity, which can be applied to other helicases.


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