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K Morihara

Publications and source records attributed to K Morihara.

At least 19 recordsLinked to original sources
PubMed1992

Structural gene and complete amino acid sequence of Vibrio alginolyticus collagenase.

The DNA encoding the collagenase of Vibrio alginolyticus was cloned, and its complete nucleotide sequence was determined. When the cloned gene was ligated to pUC18, the Escherichia coli expression vector, bacteria carrying the gene exhibited both collagenase antigen and collagenase activity. The open reading frame from the ATG initiation codon was 2442 bp in length for the collagenase structural gene. The amino acid sequence, deduced from the nucleotide sequence, revealed that the mature collagenase consists of 739 amino acids with an Mr of 81875. The amino acid sequences of 20 polypeptide fragments were completely identical with the deduced amino acid sequences of the collagenase gene. The amino acid composition predicted from the DNA sequence was similar to the chemically determined composition of purified collagenase reported previously. The analyses of both the DNA and amino acid sequences of the collagenase gene were rigorously performed, but we could not detect any significant sequence similarity to other collagenases.

Amino Acid Sequence↗
PubMed1991

Detection of elastase production in Escherichia coli with the elastase structural gene from several non-elastase-producing strains of Pseudomonas aeruginosa.

The elastase structural gene from Pseudomonas aeruginosa IFO 3455 has been cloned and sequenced. Using this gene as a probe, we cloned the DNA fragments (pEL3080R, pEL10, and pEL103R) of the elastase gene from non-elastase-producing strains (P. aeruginosa IFO 3080, N-10, and PA103 respectively). These three Pseudomonas strains showed no detectable levels of elastase antigenicity by Western blotting (immunoblotting) or by elastase activity. When elastase structural genes about 8 kb in length were cloned into pUC18, an Escherichia coli expression vector, we were able to detect both elastase antigenicity and elastolytic activity in two bacterial clones (E. coli pEL10 and E. coli pEL103R). However, neither elastolytic activity nor elastase antigenicity was detected in the E. coli pEL3080R clone, although elastase mRNA was observed. The partial restriction map determined with several restriction enzymes of these three structural genes corresponded to that of P. aeruginosa IFO 3455. We sequenced the three DNA segments of the elastase gene from non-elastase-producing strains and compared the sequences with those from the elastase-producing P. aeruginosa strains IFO 3455 and PAO1. In P. aeruginosa N-10 and PA103, the sequences were almost identical to those from elastase-producing strains, except for several nucleotide differences. These minor differences may reflect a microheterogeneity of the elastase gene. These results suggest that two of the non-elastase-producing strains have the normal elastase structural gene and that elastase production is repressed by regulation of this gene expression in P. aeruginosa. Possible reasons for the lack of expression in these two strains are offered in this paper. In P. aeruginosa IFO 3080, the sequence had a 1-base deletion in the coding region, which should have caused a frameshift variation in the amino acid sequence. At present, we have no explanation for the abnormal posttransciptional behavior of this strain.

Amino Acid Sequence↗
PubMed1991

Thermolysin catalyzed semisynthesis of peptide hormones by introduction of Phe-NH2 or Tyr-NH2 at the carboxyl termini.

The semisynthesis of C-terminal peptides of gastrin, calcitonin gene-related peptides (rat and human), and cholecystokinin, or of human neuropeptide Y was achieved by introduction of Phe-NH2 or Tyr-NH2 at their carboxyl termini, respectively. Thermolysin or the related enzyme was used for the purpose. The coupling was usually performed in the presence of high concentration of organic cosolvent, where the secondary hydrolysis was negligibly small.

Amino Acid Sequence↗
PubMed1990

Degradation of IgA proteins by Pseudomonas aeruginosa elastase.

Human colostral IgA and myeloma proteins of both IgA1 and IgA2 subclasses were susceptible to cleavage by Pseudomonas aeruginosa elastase. Detailed analysis of the cleavage products of IgA myeloma proteins revealed complete degradation of Fab with no evidence of intact Fab fragments as intermediate cleavage products. In contrast, both IgA1 and IgA2 proteins were resistant to cleavage by alkaline protease from P. aeruginosa. The susceptibility of human IgA proteins to elastase suggests a mechanism by which P. aeruginosa might evade the potentially protective function of IgA by producing this enzyme.

Bacterial Toxins↗
PubMed1990

Molecular cloning and partial DNA sequencing of the collagenase gene of Vibrio alginolyticus.

DNA fragments Vibrio alginolyticus chemovar iophagus, at least 7 kb in length, were ligated to Escherichia coli expression vectors. Three clones of Escherichia coli HB101 (pLCO-1, pLCO-2, pLCO-3) were obtained by the colony immunoblotting method using anti-collagenase antibody. In Escherichia coli, all these genes produced collagenase antigens which were detected with Western blotting. The amino acid sequence of chemically purified collagenase fragments was also analyzed. An approximately 2.5 kb DNA fragment of the pLCO-1 clone was sequenced, and we found that portions of the deduced amino acid sequence of the chemically analyzed fragments. Therefore, it is highly probable that the gene studied in the present experiment is truly a collagenase structural gene.

Amino Acid Sequence↗
PubMed1990

Complete nucleotide sequence of the structural gene for alkaline proteinase from Pseudomonas aeruginosa IFO 3455.

The DNA-encoding alkaline proteinase (AP) of Pseudomonas aeruginosa IFO 3455 was cloned, and its complete nucleotide sequence was determined. When the cloned gene was ligated to pUC18, the Escherichia coli expression vector, the gene-incorporated bacteria expressed high levels of both AP activity and AP antigens. The amino acid sequence deduced from the nucleotide sequence revealed that the mature AP consists of 467 amino acids with a relative molecular weight of 49,507. The amino acid composition predicted from the DNA sequence was similar to the chemically determined composition of purified AP reported previously. The amino acid sequence analysis revealed that both the N-terminal side sequence of the purified AP and several internal lysyl peptide fragments were identical to the deduced amino acid sequences. The percent homology of amino acid sequences between AP and Serratia protease was about 55%. The zinc ligands and an active site of the AP were predicted by comparing the structure of the enzyme with of Serratia protease, thermolysin, Bacillus subtilis neutral protease, and Pseudomonas elastase.

Amino Acid Sequence↗
PubMed1989

Structural gene and complete amino acid sequence of Pseudomonas aeruginosa IFO 3455 elastase.

The DNA encoding the elastase of Pseudomonas aeruginosa IFO 3455 was cloned, and its complete nucleotide sequence was determined. When the cloned gene was ligated to pUC18, the Escherichia coli expression vector, bacteria carrying the gene exhibited high levels of both elastase activity and elastase antigens. The amino acid sequence, deduced from the nucleotide sequence, revealed that the mature elastase consisted of 301 amino acids with a relative molecular mass of 32,926 daltons. The amino acid composition predicted from the DNA sequence was quite similar to the chemically determined composition of purified elastase reported previously. We also observed nucleotide sequence encoding a signal peptide and "pro" sequence consisting of 197 amino acids upstream from the mature elastase protein gene. The amino acid sequence analysis revealed that both the N-terminal sequence of the purified elastase and the N-terminal side sequences of the C-terminal tryptic peptide as well as the internal lysyl peptide fragment were completely identical to the deduced amino acid sequences. The pattern of identity of amino acid sequences was quite evident in the regions that include structurally and functionally important residues of Bacillus subtilis thermolysin.

Amino Acid Sequence↗
PubMed1988

Cloning and characterization of elastase structural gene from Pseudomonas aeruginosa IFO 3455.

An 8.3 Kb DNA fragment was cloned from Pseudomonas aeruginosa IFO 3455. This fragment-containing Escherichia clone, pEL2, produced a high level of elastase activity. A smaller EcoRI-KpnI fragment was subcloned into pUC118 and E. coli HB101 was transformed with the plasmid. A deletion mutant clone was also constructed in the same bacteria. These deletion mutants were tested for elastase activity and it became clear that the full length of the elastase gene was 1.0-1.3 Kb. DNA sequencing analysis revealed that this DNA fragment contains the DNA sequence coding N-terminal amino acid sequence of the elastase protein.

Amino Acid Sequence↗
PubMed1988

Enzymatic synthesis of delta sleep-inducing peptide.

The delta sleep-inducing peptide was assembled enzymatically from three tripeptide fragments. All the peptide bonds were prepared by either papain- or alpha-chymotrypsin-mediated synthesis. Secondary hydrolysis was suppressed by introducing N alpha-protected amino acid or peptide esters as carboxyl components and using an alkaline pH. The protected nonapeptide was oxidized with ferric chloride to deprotect the C-terminal phenylhydrazide and then hydrogenated. The homogeneous peptide was obtained by reversed phase high-performance liquid chromatography. Comparison of enzymatic and chemical preparations showed no obvious differences.

Amino Acid Sequence↗
PubMed1986

Influence of temperature on the enzymic semisynthesis of human insulin by coupling and transpeptidation methods.

The influence of temperature of enzymic semisynthesis of human insulin ester was determined by using coupling and transpeptidation methods with trypsin and Achromobacter lyticus proteinase I as catalysts. The optimal reaction conditions were studied at the selected temperatures of 25, 12 and 4 degrees C. The results showed that the synthesis rates by both methods with trypsin increased as the temperature increased, but the final product yield correspondingly decreased. Therefore the reaction with trypsin should be done below 12 degrees C, preferably at 4 degrees C. This agrees well with the stability of trypsin at these temperatures. When the catalyst was Achromobacter lyticus proteinase I, no such complex temperature effects were observed, and the findings indicated that the reactions should be conducted below 37 degrees C for enzyme stability.

Catalysis↗
PubMed1986

Comparison of the subsite specificity of the mammalian neutral endopeptidase 24.11 (enkephalinase) to the bacterial neutral endopeptidase thermolysin.

A comparison has been made of the specificity of the mammalian neutral metalloendopeptidase, endopeptidase 24.11, with that of the bacterial neutral metalloendopeptidase thermolysin. A series of synthetic oligopeptides which have previously been studied as substrates for thermolysin and used in computer modeling were examined as substrates for the mammalian enzyme. It was found that P1, P2, and P'3 subsite interactions in the mammalian enzyme, although similar to those found in thermolysin, are less restrictive spatially and are considerably less dependent on hydrophobic interactions. This difference was maximally expressed with the synthetic substrate dansyl-D-alanylglycylnitrophenylalanylglycine which is a substrate for the mammalian enzyme, but not for the bacterial enzyme. A comparison of substrates in the free acid form with their corresponding amides showed that binding to the mammalian enzyme is dependent in part on an ionic interaction between the substrate carboxylate group and the enzyme. Such an ionic interaction was not observed with the bacterial enzyme.

Amino Acid Sequence↗
PubMed1986

Affinity purification of kallikrein and elastase from hog pancrease powder.

The present report describes a method that is efficient for simultaneous isolation of kallikrein and elastase from hog pancrease powder. Both enzymes were separated by successive column chromatography on CM-cellulofine and p-aminobenzamidine-Sepharose 4B. Kallikrein was further purified by column chromatography on DEAE-Sephadex and elastase was purified by repeated gel chromatography on Sephadex G-75. The kallikrein obtained was composed of two components, which were separable by sodium dodecyl sulphate polyacrylamide gel electrophoresis, and the elastase had one component. The activity yields of kallikrein and elastase were 49 and 38%, respectively.

Amino Acids↗