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Biomedical subjects

M Yaguchi

Publications and source records attributed to M Yaguchi.

At least 91 records · Page 5Linked to original sources
PubMed1985

The role of carboxyl groups in the function of endo-beta-1,4-glucanase from Schizophyllum commune.

The endo-beta-1,4-glucanase from Schizophyllum commune was purified to homogeneity by a modified procedure that employed concanavalin A-Sepharose. The catalytic site of the enzyme has previously been proposed to consist of Glu-33 and Asp-50 that act in a manner analogous to lysozyme [Yaguchi, M., Roy, C., Rollin, C.F., Paice, M.G. & Jurasek, L. (1983) Biochem. Biophys. Res. Commun. 116, 408-411]. The role of carboxyl groups in the mechanism of action was delineated through kinetic and chemical modification studies. The rate of endoglucanase-catalysed hydrolysis of CM-cellulose was determined viscometrically at 30 degrees C, 0.06 M ionic strength and pH 2.5-9.0. The pH profile for maximum velocity gave the kinetic apparent pK values 3.8 and 6.6 and for initial velocity the pK values 3.7 and 6.1. Treatment of the endoglucanase with diethylpyrocarbonate resulted in the modification of all the four histidyl residues present in the enzyme with the retention of 95% of the original enzymatic activity. A water-soluble carbodiimide completely inactivated the cellulase and kinetic analysis indicated that at least one molecule of carbodiimide binds to the enzyme for inactivation. The pH dependence of the inactivation is consistent with the modification of carboxyl groups. The binding of an inhibitor, cellobiose, prior to carbodiimide modification protected the enzyme from rapid inactivation. Titration of the enzyme with dithiobis(2-nitrobenzoic acid) indicated the absence of free thiol groups. Reaction of the endoglucanase with tetranitromethane resulted in the modification of six of the fourteen tyrosyl residues of the enzyme with approximately 35% diminution in activity.

Agaricales↗
PubMed1985

Glucanase gene diversity in prokaryotic and eukaryotic organisms.

A number of bacteria and eukaryotes produce extracellular enzymes that degrade various types of polysaccharides including the glucans starch, cellulose and hemicellulose (xylan). The similarities in the modes of expression and specificity of enzyme classes, such as amylase, cellulose and xylanase, suggest common genetic origins for particular activities. Our determination of the extent of similarity between these glucanases suggests that such data may be of very limited use in describing the early evolution of these proteins. The great diversity of these proteins does allow identification of their most highly conserved (and presumably functionally important) regions.

Amino Acid Sequence↗
PubMed1984

The 5S RNA binding protein from yeast (Saccharomyces cerevisiae) ribosomes. An RNA binding sequence in the carboxyl-terminal region.

The carboxyl-terminal half (CN2 fragment) of the yeast 5S RNA binding protein (YL3) retains an ability to form homogeneous ribonucleoprotein complexes with RNA although the N-terminal half (CN1) appears to confer specificity for the 5S RNA molecule [Nazar, R.N., Yaguchi, M., Willick, G.E., Rollin, C.F. and Roy, C. (1979) Eur. J. Biochem. 102, 573-582]. The nucleic acid binding site in this fragment was more clearly delineated by cleaving the CN2 fragment with a variety of enzymatic and chemical reagents and further examining the ability of the products to form RNA-peptide complexes. Hot acetic acid treatment produced a 47-residue subfragment (CN2-A1) which originated from the C terminus and continued to form stable ribonucleopeptide complexes. The amino acid sequence of this subfragment was determined to be: -Pro-Ala-Phe-Lys-Pro-Thr-Glu-Lys50-Phe-Thr-Lys-Glu-Gln-Tyr-Ala-Ala -Glu60-Ser-Ly s -Lys-Tyr-Arg-Gln-Thr-Lys-Leu-Ser70-Lys-Gln-Gln-Arg-Ala-Ala-Arg-Val -Ala-Ala80-Ly s -Ile-Ala-Ala-Leu-Ala-Gly-Gln-Gln-COOH, with 12 of the 16 basic residues in the CN2 fragment being present in this binding site. The amino acid sequence of the CN2-A1 fragment bears a limited homology in both amino acid and charge distribution with histone 2B from mammals and with one of the 5S RNA binding proteins (EL25) from Escherichia coli. The results suggest that many protein binding sites for nucleic acids may share common structural features and further support the notion that the single large eukaryotic 5S RNA protein may have evolved through a fusion of genes for the multiple 5S RNA binding proteins in prokaryotes.

Amino Acid Sequence↗
PubMed1984

Applications of recombinant DNA technology to the pulp and paper industry.

New gene selection techniques (Recombinant DNA) are currently available to exploit useful properties of various biological systems hitherto regarded as interesting but of little or no immediate commercial value. The application of genetic engineering techniques to problems in the Pulp and Paper Industry are many. As a first step these techniques are being used to provide much needed fundamental information on the cellular and molecular mechanisms involved in the expression of extra-cellular enzymes that degrade lignocellulosic pulping wastes. The information gleaned from the studies on cellulolytic fungi and bacteria can be used to genetically engineer a yeast or bacterium capable of converting pulping wastes into ethanol and other useful by-products.

Journal Article↗
PubMed1984

Extracellular proteins secreted by the basidiomycete Schizophyllum commune in response to carbon source.

The secretion of 1,4-beta-D-glucanases by the basidiomycete Schizophyllum commune in response to cellulose or cellobiose has been studied. The proteins were labeled with 35S, and the secretion of enzymes was measured by beta-glucosidase and carboxymethyl cellulase activities and by immunoprecipitation with specific antibodies. The antigen proteins used were a beta-glucosidase (Mr, 93,000), an avicelase (avicelase II; Mr, 64,000), and a carboxymethyl cellulose (carboxymethyl cellulase I; Mr 41,000). The beta-glucosidase was initially secreted as an Mr 110,000 form, which was followed later by lower-molecular-weight (88,000 to 93,000) forms. The avicelase II, which accounted for about 50% of the secreted labeled protein, had an Mr of 64,000. Secretion of the related avicelase I (Mr 61,000) followed later. The carboxymethyl cellulose I was secreted in two molecular weight forms, Mr 44,000 and 41,000. The evidence is consistent with the idea that three genes account for the secreted glucanase activities. Other species result from different glycosylation or proteolytic cleavage processing, which may occur during or after secretion. The beta-glucosidase secretion appears to be regulated differently than that of avicelase II or carboxymethyl cellulase I; the latter two were regulated coordinately under the conditions used in this work. No common immune determinants between the three antigens were observed.

Agaricales↗
PubMed1984

Purification, properties, and N-terminal amino acid sequence of certain 50S ribosomal subunit proteins from the archaebacterium Halobacterium cutirubrum.

Sixteen ribosomal proteins (r-proteins) from the 50S ribosomal subunit of the archaebacterium Halobacterium cutirubrum have been purified and their amino acid composition and partial N-terminal amino acid sequence have been determined. These proteins as a group are much more acidic than the large subunit r-proteins from eubacteria or eukaryotes. Little sequence homology is evident between the 50S subunit archaebacterial r-proteins and the equivalent proteins from the eubacterium Escherichia coli.

Amino Acid Sequence↗
PubMed1983

A fungal cellulase shows sequence homology with the active site of hen egg-white lysozyme.

The N-terminal amino acid sequence of an endo-beta-1,4-glucanase from the cellulase complex of the white-rot fungus Schizophyllum commune has been determined. The sequence from Glu-33 to Tyr-51 was homologous with the active site sequences of various hen egg-white type lysozymes, including lysozyme catalytic residues (Glu-35, Asp-52) and substrate binding residue Asn-44. The homology offers evidence for a lysozyme-type mechanism in enzymic hydrolysis of cellulose.

Agaricales↗
PubMed1983

The complete amino acid sequence of oncomodulin--a parvalbumin-like calcium-binding protein from Morris hepatoma 5123tc.

Oncomodulin is an acidic calcium-binding protein of 108 amino acids which has been detected only in tumors. The complete amino acid sequence of rat oncomodulin has been established, and the N-terminus shown to be N-acetylserine. Homology of the oncomodulin sequence with members of the troponin C superfamily of calcium-binding proteins was demonstrated, and putative calcium-binding domains were located. A further degree of homology was established between oncomodulin and the parvalbumins, including rat parvalbumin. Oncomodulin was therefore considered to be a parvalbumin-like calcium-binding protein.

Amino Acid Sequence↗
PubMed1983

The monomeric glutamyl-tRNA synthetase from Bacillus subtilis 168 and its regulatory factor. Their purification, characterization, and the study of their interaction.

The glutamyl-tRNA synthetase from Bacillus subtilis has been purified to homogeneity. It is a monomer of Mr = 65,500 whose NH2-terminal sequence is Met-Asn-Glu-Val-Arg-Val-Arg-Tyr-Ser-Pro-Ser-Pro-Thr-Gly-His-Leu. The number of tryptic peptides indicates the absence of a significant amount of sequence duplication. Under certain conditions, this monomeric enzyme is co-purified with a polypeptide beta of Mr = 46,000, which increases the affinity of the enzyme about 10-fold for glutamate and for ATP, and stabilizes it against heat inactivation. gamma-Globulins prepared against the monomeric enzyme can inhibit completely the glutamyl-tRNA synthetase activity of a B. subtilis extract and precipitate from this extract both the monomeric enzyme and the regulatory factor beta. These anti-alpha immunoglobulins do nt precipitate pure beta. These results show that the glutamyl-tRNA synthetase of B. subtilis has a structure similar to that of the Escherichia coli enzyme (Lapointe, J., and Söll, D. (1972) J. Biol. Chem. 247, 4966-4974) and indicate that the beta factor has a function in the regulation of glutamyl-tRNA biosynthesis in vivo.

Amino Acid Sequence↗
PubMed1983

A new member of the troponin C superfamily: comparison of the primary structures of rat oncomodulin and rat parvalbumin.

When the amino-acid sequence of the 108-residue, rat tumour calcium-binding protein, oncomodulin, was aligned with that of rat muscle parvalbumin, 55 homologous positions were found, with an additional 33 single base-pair substitutions. This extensive homology, with virtual identity of the calcium-binding domains, signalled oncomodulin to be a member of the troponin C superfamily. The presence of Cys-18 and Phe-66 in oncomodulin, plus its isoelectric point of 3.9, suggest that this tumour protein is a beta-parvalbumin, rather than a muscle alpha-parvalbumin.

Amino Acid Sequence↗
PubMed1983

Comparison of plasmids Co1E2-P9 and Co1E2-CA42 and their immunity proteins.

Plasmids ColE2-CA42 (6.1 kilobases) and ColE2-P9 (6.8 kilobases) were found to have homologous (4.3-kilobase) DNA segments which contain their colicin and immunity genes. The relatedness of their immunity proteins was verified by determining their amino acid compositions and N-terminal sequences. These characteristics were compared with those of ColE3-CA38.

Bacteriocin Plasmids↗
PubMed1982

The 5S RNA - protein complex from yeast: a model for the evolution and structure of the eukaryotic ribosome.

The ribosomal 5S RNA - protein complex appears to be an excellent model for studies on the evolution and structure of ribosomes. In eukaryotes this complex is composed of two components, the 5S rRNA and a single ribosomal protein which in yeast has a molecular weight of about 38 000. The primary protein-binding site is located in the 3' -end region of the 5S RNA together with a small portion of the 5' end. The primary RNA-binding site appears to be situated in the C-terminal end of the protein (YL3 in yeast) but the binding specificity requires other structural elements in the N-terminal half of the molecule. When compared with prokaryotic 5S RNA - protein complexes, various physical and chemical studies suggest that the basic structure and interactions have been conserved in the course of evolution, but that the single larger eukaryotic 5S RNA binding protein has evolved through a fusion of genes for the multiple 5S RNA binding proteins in prokaryotes.

Bacterial Proteins↗
PubMed1982

Structural comparison of the lectin from sainfoin (Onobrychis viciifolia) with concanavalin A and other D-mannose specific lectins.

The D-mannose specific lectin from sainfoin was prepared by affinity chromatography on Sephadex G-75, and its circular dichroism (CD), metal content, antigenic character, and N-terminal amino acid sequence were compared with those of four lectins from Vicieae plants and concanavalin A. The sainfoin lectin was only slightly more closely related to these other D-mannose specific lectins, than to lectins of leguminous plants in general. The CD and antigenic experiments also confirmed the close relationship of the four Vicieae lectins. The N-terminal sequence showed sainfoin has two isolectins, differing in sequence at residue four. The sequence was homologous to N-terminal sequences of several other lectins; hence, despite some structural and specificity similarities, the sainfoin lectin does not show the circular permutation of sequence unique to concanavalin A. This region also contained the sole cysteine residue, at position 33. The carbohydrate-binding properties of the sainfoin lectin were studied by gradient affinity chromatography. Its apparent Ka for methyl alpha-D-glucoside was approximately 10(3) M-1, close to the Ka of the pea lectin. However, in the relative binding behaviour of methyl alpha-D-mannoside, maltose, and methyl alpha-D-glucoside, it resembled concanavalin A more than the pea lectin.

Amino Acid Sequence↗
PubMed1980

Sequence homologies in the N-terminal region of the ribosomal 'A' proteins from Methanobacterium Thermoautotrophicum and Halobacterium cutirubrum.

The ribosomal 'A' protein from the methanogen, Methanobacterium thermoautotrophicum, has been isolated and purified. The amino acid composition and mobility on two-dimensional gels indicates that this protein shows characteristics similar to the equivalent protein from the extreme halophile, Halobacterium cutirubrum, and is significantly different from the equivalent protein from other bacteria. The first 48 residues of the methanogenic 'A' protein were sequenced and showed a large amount of sequence homology to the H. cutirubrum 'A' protein. When the sequences of these two proteins were compared to the 'A' protein from other procaryotes (eubacteria), much less homology was evident. These results support the hypothesis (Woese, C.R. and Fox, G.F., (1977) Proc. Natl. Acad. Sci. U.S.A. 74, 5088-5090) of two procaryotic lines of evolutionary descent, the eubacteria and the archaebacteria, the latter including the methanogens and the extreme halophiles. The sequence data from the 'A' proteins also indicate that, phylogenetically, the archaebacteria are much closer to the cytoplasmic components of eucaryotes than they are to the eubacteria (or 'true bacteria').

Amino Acid Sequence↗
PubMed1979

The 5-S RNA binding protein from yeast (Saccharomyces cerevisiae) ribosomes. Evolution of the eukaryotic 5-S RNA binding protein.

The ribonucleoprotein complex between 5-S RNA and its binding protein (5-S RNA . protein complex) of yeast ribosomes was released from 60-S subunits with 25 mM EDTA and the protein component was purified by chromatography on DEAE-cellulose. This protein, designated YL3 (Mr = 36000 on dodecylsulfate gels), was relatively insoluble in neutral solutions (pH 4--9) and migrated as one of four acidic 60-S subunit proteins when analyzed by the Kaltschmidt and Wittman two-dimensional gel system. Amino acid analyses indicated lower amounts of lysine and arginine than most ribosomal proteins. Sequence homology was observed in the N terminus of YL3, and two prokaryotic 5-S RNA binding proteins, EL18 from Escherichia coli and HL13 from Halobacterium cutirubrum: Ala1-Phe2-Gln3-Lys4-Asp5-Ala6-Lys7-Ser8-Ser9-Ala10-Tyr11-Ser12-Ser13-Arg14-Phe15-Gln16-Tyr17-Pro18-Phe19-Arg20-Arg21-Arg22-Arg23-Glu24-Gly25-Lys26-Thr27-Asp28-Tyr29-Tyr35; of particular interest was homology in the cluster of basic residues (18--23). Since the protein contained one methionine residue it could be split into two fragments, CN1 (Mr = 24700) and CN2 (Mr = 11300) by CNBr treatment; the larger fragment originated from the N terminus. The N-terminal amino acid sequence of CN2 shared a limited sequence homology with an internal portion of a second 5-S RNA binding protein from E. coli, EL5, and, based also on the molecular weights of the proteins and studies on the protein binding sites in 5-S RNAs, a model for the evolution of the eukaryotic 5-S RNA binding protein is suggested in which a fusion of the prokaryotic sequences may have occurred. Unlike the native 5-S RNA . protein complex, a variety of RNAs interacted with the smaller CN2 fragment to form homogeneous ribonucleoprotein complexes; the results suggest that the CN1 fragment may confer specificity on the natural 5-S RNA-protein interaction.

Amino Acid Sequence↗