scholarly journals Reaction mechanism of chitobiose phosphorylase from Vibrio proteolyticus: identification of family 36 glycosyltransferase in Vibrio

2004 ◽  
Vol 377 (1) ◽  
pp. 225-232 ◽  
Author(s):  
Yuji HONDA ◽  
Motomitsu KITAOKA ◽  
Kiyoshi HAYASHI

A family 36 glycosyltransferase gene was cloned from Vibrio proteolyticus. The deduced amino acid sequence showed a high degree of identity with ChBP (chitobiose phosphorylase) from another species, Vibrio furnissii. The recombinant enzyme catalysed the reversible phosphorolysis of (GlcNAc)2 (chitobiose) to form 2-acetamide-2-deoxy-α-d-glucose 1-phosphate [GlcNAc-1-P] and GlcNAc, but showed no activity on cellobiose, indicating that the enzyme was ChBP, not cellobiose phosphorylase. In the synthetic reaction, the ChBP was active with α-d-glucose 1-phosphate as the donor substrate as well as GlcNAc-1-P to produce β-d-glucosyl-(1→4)-2-acetamide-2-deoxy-d-glucose with GlcNAc as the acceptor substrate. The enzyme allowed aryl-β-glycosides of GlcNAc as the acceptor substrate with 10–20% activities of GlcNAc. Kinetic parameters of (GlcNAc)2 in the phosphorolysis and GlcNAc-1-P in the synthetic reaction were determined as follows: phosphorolysis, k0=5.5 s−1, Km=2.0 mM; synthetic reaction, k0=10 s−1, Km=14 mM, respectively. The mechanism of the phosphorolytic reaction followed a sequential Bi Bi mechanism, as frequently observed with cellobiose phosphorylases. Substrate inhibition by GlcNAc was observed in the synthetic reaction. The enzyme was considered a unique biocatalyst for glycosidation.

1980 ◽  
Vol 45 (4) ◽  
pp. 1144-1154 ◽  
Author(s):  
Miroslav Baudyš ◽  
Helena Keilová ◽  
Vladimír Kostka

To determine the primary structure of the C-terminal part of the molecule of chicken pepsinogen the tryptic, chymotryptic and thermolytic digest of the protein were investigated and peptides derived from this region were sought. These peptides permitted the following 21-residue C-terminal sequence to be determined: ...Ile-Arg-Glu-Tyr-Tyr-Val-Ile-Phe-Asp-Arg-Ala-Asn-Asn-Lys-Val-Gly-Leu-Ser-Pro-Leu-Ser.COOH. A comparison of this structure with the C-terminal sequential regions of the other acid proteases shows a high degree of homology between chicken pepsinogen and these proteases (e.g., the degree of homology with respect to hog pepsinogen and calf prochymosin is about 66%). Additional tryptic peptides, derived from the N-terminal part of the zymogen molecule whose amino acid sequence has been reported before, were also obtained in this study. This sequence was extended by two residues using an overlapping peptide. An ancillary result of this study was the isolation of tryptic peptides derived from other regions of the zymogen molecule.


2001 ◽  
Vol 183 (6) ◽  
pp. 1954-1960 ◽  
Author(s):  
Grit Zarnt ◽  
Thomas Schräder ◽  
Jan R. Andreesen

ABSTRACT The quinohemoprotein tetrahydrofurfuryl alcohol dehydrogenase (THFA-DH) from Ralstonia eutropha strain Bo was investigated for its catalytic properties. The apparentk cat/Km andK i values for several substrates were determined using ferricyanide as an artificial electron acceptor. The highest catalytic efficiency was obtained with n-pentanol exhibiting a k cat/Km value of 788 × 104 M−1 s−1. The enzyme showed substrate inhibition kinetics for most of the alcohols and aldehydes investigated. A stereoselective oxidation of chiral alcohols with a varying enantiomeric preference was observed. Initial rate studies using ethanol and acetaldehyde as substrates revealed that a ping-pong mechanism can be assumed for in vitro catalysis of THFA-DH. The gene encoding THFA-DH from R. eutropha strain Bo (tfaA) has been cloned and sequenced. The derived amino acid sequence showed an identity of up to 67% to the sequence of various quinoprotein and quinohemoprotein dehydrogenases. A comparison of the deduced sequence with the N-terminal amino acid sequence previously determined by Edman degradation analysis suggested the presence of a signal sequence of 27 residues. The primary structure of TfaA indicated that the protein has a tertiary structure quite similar to those of other quinoprotein dehydrogenases.


The complete amino acid sequence of yeast phosphoglycerate mutase comprising 241 residues has been determined. The sequence was deduced from the two cyanogen bromide fragments, and from the peptides derived from these fragments after digestion by a number of proteolytic enzymes. Determination of this sequence now allows a detailed interpretation of the existing high-resolution X-ray crystallographic structure. A comparison of the sequence reported here with the sequences of peptides from phosphoglycerate mutases from other species, and with the sequence of erythrocyte diphosphoglycerate mutase, indicates that these enzymes have a high degree of structural homology. Autolysis of phosphoglycerate mutase by yeast extracts leads to the complete loss of mutase activity, and the formation of electrophoretically distinguishable forms (R. Sasaki, E. Sugimoto & H. Chiba, Archs Biochem. Biophys. 115, 53-61 (1966)). It is apparent from the amino acid sequence that these changes are due to the loss of an 8─12 residue peptide from the C-terminus.


1989 ◽  
Vol 44 (7) ◽  
pp. 817-824 ◽  
Author(s):  
Aftab Ahmed ◽  
Meeno Jahan ◽  
Gerhard Braunitzer ◽  
Helmut Pechlaner

The complete amino acid sequences of the hemoglobins from the adult European polecat (Mustela putorius) are presented. The erythrocytes contain two hemoglobin components and three globin chains (α I, α II and β). The primary structure of globin chains and of the tryptic peptides determined in liquid- and gas-phase sequantors. Comparing the sequences of the globin chains of the polecat with that of human Hb-A, 17 (23.9%) substitutions were recognized in the α I, 16 (22.5%) in the α II and 14 (20.4%) in the β chain. A high degree of homology observed with other representatives of the family Mustelidae.


1987 ◽  
Vol 246 (1) ◽  
pp. 115-120 ◽  
Author(s):  
R P Ambler ◽  
T E Meyer ◽  
M A Cusanovich ◽  
M D Kamen

The amino acid sequence of the principal soluble cytochrome c from the phototrophic acidophilic bacterium Rhodopseudomonas (or Rhodopila) globiformis was determined. By the criteria of percentage sequence identity and fewness of internal insertions and deletions it is more similar in sequence to some mitochondrial cytochromes c than to any known bacterial cytochrome. The organism does not have any properties that commend it as being particularly similar to postulated prokaryotic precursors of the mitochondrion. We consider that the relatively high degree of sequence similarity is an instance of convergence, and is an example of the limitations that are imposed on attempts to deduce distant evolutionary relationships from sequence information. Detailed evidence for the amino acid sequence of the protein has been deposited as Supplementary Publication SUP 50136 (12 pages) at the British Library Lending Division, Boston Spa, West Yorkshire LS23 7BQ, U.K., from whom copies are available on prepayment [see Biochem. J. (1987) 241, 5].


1973 ◽  
Vol 138 (2) ◽  
pp. 410-427 ◽  
Author(s):  
J. Donald Capra ◽  
Richard L. Wasserman ◽  
J. Michael Kehoe

Immunoglobulin heavy chains from IgG pools of several mammalian species have been subjected to Edman degradation on an automated protein sequencer. The percentage of unblocked vs. blocked heavy chains was estimated from the yield of the invariant valine in the second position. Further analysis of these unblocked polypeptides unequivocally placed them in the VHIII subgroup on the basis of homology with known human heavy chain sequences. The mammals studied could be divided into three distinct categories on the basis of the distribution of the VHIII subgroup. In several species the VHIII subgroup could not be detected while, in others, virtually all of the heavy chains belonged to this subgroup. Several species had intermediate amounts with the level of the VHIII subgroup restricted to between 19 and 29% of the total pool. Within experimental error, all members of a given order had a similar VHIII subgroup distribution. Further amino acid sequence studies illustrated a high degree of structural homogeneity in the heavy chains of IgG isolated from pooled sera of a number of mammalian species. The very close amino acid sequence homologies of the amino terminal 24 residues of the various pools corroborated conclusions previously obtained using several myeloma proteins from some of these same species. In particular, certain phylogenetically associated residues were identifiable at characteristic positions in the pools in confirmation of their identification in the myeloma proteins. The simplest assumptions would suggest that these findings are more compatible with a pauci-gene than a multi-gene basis for the generation of antibody diversity.


1992 ◽  
Vol 12 (12) ◽  
pp. 5600-5609 ◽  
Author(s):  
L W Burrus ◽  
M E Zuber ◽  
B A Lueddecke ◽  
B B Olwin

The fibroblast growth factor (FGF) family consists of seven members whose activities are thought to be mediated by multiple receptors. Here we describe the cDNA cloning, expression, and characterization of a cysteine-rich FGF receptor (CFR) that is distinct from previously identified FGF receptors. The deduced amino acid sequence for CFR suggests that it is an integral membrane protein containing a large extracellular domain comprising 16 cysteine-rich repeated units and an intracellular domain of 13 amino acids. No reported sequences exhibit significant homologies to either the repeated extracellular motif or to the entire CFR amino acid sequence. Several CFR transcripts are present in embryonic chick tissue, suggesting that CFR undergoes alternate mRNA splicing or that related genes are present. Chinese hamster ovary cells transfected with the CFR cDNA express a 150-kDa polypeptide that binds FGF-1, FGF-2, and FGF-4 but does not bind several non-FGF family members. The high degree of evolutionary conservation among vertebrate CFRs and its ability to bind three different FGFs with high affinity suggest that this unique receptor plays an important role in FGF biology.


1986 ◽  
Vol 235 (3) ◽  
pp. 769-773 ◽  
Author(s):  
J R Vanfleteren ◽  
S M Van Bun ◽  
L L Delcambe ◽  
J J Van Beeumen

The complete amino acid sequence of histone H2B from the nematode Caenorhabditis elegans was determined. The protein as obtained by us is a mixture of multiple forms. Approx. 90% of the molecules consist of a polypeptide chain of 122 amino acids with alanine as N-terminal residue and proline at the second position. In the remaining 10% alanine is lacking and the chain starts with proline. In addition to the heterogeneity of chain length, polymorphism occurs at the positions 7 (Ala/Lys), 14 (Ala/Lys) and 72 (Ala/Ser) of the major chain and at position 6 (Ala/Lys) of the shorter chain. In the N-terminal third of the molecule there is a high degree of sequence homology to the corresponding region in H2B from Drosophila (insect), Patella (mollusc) and Asterias (starfish). In contrast, this part of the molecule differs considerably from mammalian histone H2B.


2009 ◽  
Vol 78 (3) ◽  
pp. 1185-1192 ◽  
Author(s):  
Hidetaka Nakagaki ◽  
Shinichi Sekine ◽  
Yutaka Terao ◽  
Masahiro Toe ◽  
Muneo Tanaka ◽  
...  

ABSTRACT We have previously shown that one of the minimal active regions of statherin, a human salivary protein, for binding to Fusobacterium nucleatum is a YQPVPE amino acid sequence. In this study, we identified the FomA protein of F. nucleatum, which is responsible for binding to the statherin-derived YQPVPE peptide. Overlay analysis showed that a 40-kDa protein of the F. nucleatum cell envelope (40-kDa CE) specifically bound to the YQPVPE peptide. The equilibrium association constant between the affinity-purified 40-kDa CE and the YQPVPE peptide was 4.30 × 106. Further, the purity and amino acid sequence analyses of the purified 40-kDa CE revealed approximately 98.7% (wt/wt) purity and a high degree of homology with FomA, a major porin protein of F. nucleatum. Thus, a FomA-deficient mutant failed to bind to the YQPVPE peptide. In addition, increased levels of a FomA-specific mucosal IgA antibody (Ab) and plasma IgG and IgA Abs were seen only in mice immunized nasally with cholera toxin (CT) and the purified 40-kDa FomA protein. Interestingly, saliva from mice that received FomA plus CT as a mucosal adjuvant nasally prevented in vitro binding of F. nucleatum to statherin-coated polyvinyl chloride plates. Taken together, these results suggest that induction of specific immunity to the 40-kDa FomA protein of F. nucleatum, which specifically binds to the statherin-derived peptide, may be an effective tool for preventing the formation of F. nucleatum biofilms in the oral cavity.


2022 ◽  
Author(s):  
Kenneth W Adolph

Multiple metaxin-like proteins are shown to exist in fungi, as also found for the metaxin proteins of vertebrates and invertebrates. In vertebrates, metaxins 1 and 2 are mitochondrial membrane proteins that function in the import of proteins into mitochondria. Fungal metaxin-like proteins were identified by criteria including their homology with human metaxins and the presence of characteristic GST_N_Metaxin, GST_C_Metaxin, and Tom37 protein domains. Fungi in different taxonomic divisions (phyla) were found to possess multiple metaxin-like proteins. These include the Ascomycota, Basidiomycota, Blastocladiomycota, Chytridiomycota, Mucoromycota, Neocallimastigomycota, and Zoopagomycota divisions. Most fungi with multiple metaxin-like proteins contain two proteins, designated MTXa and MTXb. Amino acid sequence alignments show a high degree of homology among MTXa proteins, with over 60% amino acid identities, and also among MTXb proteins of fungi in the same division. But very little homology is observed in aligning MTXa with MTXb proteins of the same or different fungi. Both the MTXa proteins and MTXb proteins have the protein domains that characterize the metaxins and metaxin-like proteins: GST_N_Metaxin, GST_C_Metaxin, and Tom37. The metaxins and metaxin-like proteins of vertebrates, invertebrates, plants, protists, and bacteria all possess these domains. The secondary structures of MTXa and MTXb proteins are both dominated by similar patterns of α-helical segments, but extensive β-strand segments are absent. Nine highly conserved α-helical segments are present, the same as other metaxins and metaxin-like proteins. Phylogenetic analysis reveals that MTXa and MTXb proteins of fungi form two separate and distinct groups. These groups are also separate from the groups of vertebrate metaxins, metaxin-related Sam37 proteins of yeasts, and metaxin-like FAXC proteins.


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