A novel alkaline endoglucanase from an alkaliphilic Bacillus isolate: enzymatic properties, and nucleotide and deduced amino acid sequences

2001 ◽  
Vol 57 (1-2) ◽  
pp. 109-116 ◽  
Author(s):  
Endo K. ◽  
Hakamada Y. ◽  
Takizawa S. ◽  
Kubota H. ◽  
Sumitomo N. ◽  
...  
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequences ◽  
Enzymatic Properties ◽  
Alkaliphilic Bacillus ◽  
Bacillus Isolate

Nucleotide and deduced amino acid sequences of a high-molecular-mass subtilisin from an alkaliphilic Bacillus isolate

2003 ◽  
Vol 1624 (1-3) ◽  
pp. 109-114 ◽  
Author(s):  
Akinori Ogawa ◽  
Nobuyuki Sumitomo ◽  
Mitsuyoshi Okuda ◽  
Katsuhisa Saeki ◽  
Shuji Kawai ◽  
...  
Keyword(s):  
Amino Acid ◽  
Molecular Mass ◽  
High Molecular Mass ◽  
Amino Acid Sequences ◽  
Alkaliphilic Bacillus ◽  
Bacillus Isolate

Nucleotide and Deduced Amino Acid Sequences of a New Subtilisin from an Alkaliphilic Bacillus Isolate

2003 ◽  
Vol 47 (4) ◽  
pp. 337-340 ◽  
Author(s):  
Katsuhisa Saeki ◽  
Marietta V. Magallones ◽  
Yasushi Takimura ◽  
Yuji Hatada ◽  
Tohru Kobayashi ◽  
...  
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequences ◽  
Alkaliphilic Bacillus ◽  
Bacillus Isolate

Enzymatic Properties and Nucleotide and Amino Acid Sequences of a Thermostable β-Agarase from the Novel Marine Isolate, JAMB-A94

2004 ◽  
Vol 68 (5) ◽  
pp. 1073-1081 ◽  
Author(s):  
Yukari OHTA ◽  
Yuichi NOGI ◽  
Masayuki MIYAZAKI ◽  
Zhijun LI ◽  
Yuji HATADA ◽  
...  
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequences ◽  
Enzymatic Properties ◽  
The Novel ◽  
Marine Isolate

scholarly journals Two Highly Similar Chitinases from Marine Vibrio Species have Different Enzymatic Properties

Marine Drugs ◽  
2020 ◽  
Vol 18 (3) ◽  
pp. 139
Author(s):  
Xinxin He ◽  
Min Yu ◽  
Yanhong Wu ◽  
Lingman Ran ◽  
Weizhi Liu ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Extracellular Enzymes ◽  
Vibrio Harveyi ◽  
Amino Acid Sequences ◽  
Enzymatic Properties ◽  
Site Directed Mutagenesis ◽  
Amino Acid Residues ◽  
Marine Vibrio ◽  
Key Sites

Chitinase, as one of the most important extracellular enzymes in the marine environment, has great ecological and applied values. In this study, two chitinases (Chi1557 and Chi4668) with 97.33% amino acid sequences identity were individually found in Vibrio rotiferianus and Vibrio harveyi. They both were encoding by 561 amino acids, but differed in 15 amino acids and showed different enzymatic properties. The optimal temperature and pH ranges were 45–50 °C and pH 5.0–7.0 for Chi1557, while ~50 °C and pH 3.0–6.0 for Chi4668. K+, Mg2+, and EDTA increased the enzymatic activity of Chi4668 significantly, yet these factors were inhibitory to Chi1557. Moreover, Chi1557 degraded colloidal chitin to produce (GlcNAc)2 and minor GlcNAc, whereas Chi4668 produce (GlcNAc)2 with minor (GlcNAc)3 and (GlcNAc)4. The Kcat/Km of Chi4668 was ~4.7 times higher than that of Chi1557, indicating that Chi4668 had stronger catalytic activity than Chi1557. Furthermore, site-directed mutagenesis was performed on Chi1557 focusing on seven conserved amino acid residues of family GH18 chitinases. Chi1557 was almost completely inactive after Glu154, Gln219, Tyr221, or Trp312 was individually mutated, retained ~50% activity after Tyr37 was mutated, and increased two times activity after Asp152 was mutated, indicating that these six amino acids were key sites for Chi1557.

scholarly journals Enzymatic Properties of Dipeptidyl Aminopeptidase IV Produced by the Periodontal Pathogen Porphyromonas gingivalis and Its Participation in Virulence

2000 ◽  
Vol 68 (2) ◽  
pp. 716-724 ◽  
Author(s):  
Yumi Kumagai ◽  
Kiyoshi Konishi ◽  
Tomoharu Gomi ◽  
Hisao Yagishita ◽  
Ayako Yajima ◽  
...  
Keyword(s):  
Amino Acid ◽  
Porphyromonas Gingivalis ◽  
Catalytic Domain ◽  
Animal Experiments ◽  
Catalytic Triad ◽  
Amino Acid Sequences ◽  
Enzymatic Properties ◽  
Site Directed Mutagenesis ◽  
Periodontal Pathogen ◽  
Dipeptidyl Aminopeptidase

ABSTRACT Porphyromonas gingivalis is a major pathogen associated with adult periodontitis. We cloned and sequenced the gene (dpp) coding for dipeptidyl aminopeptidase IV (DPPIV) fromP. gingivalis W83, based on the amino acid sequences of peptide fragments derived from purified DPPIV. An Escherichia coli strain overproducing P. gingivalis DPPIV was constructed. The enzymatic properties of recombinant DPPIV purified from the overproducer were similar to those of DPPIV isolated fromP. gingivalis. The three amino acid residues Ser, Asp, and His, which are thought to form a catalytic triad in the C-terminal catalytic domain of eukaryotic DPPIV, are conserved in P. gingivalis DPPIV. When each of the corresponding residues of the enzyme was substituted with Ala by site-directed mutagenesis, DPPIV activity significantly decreased, suggesting that these three residues of P. gingivalis DPPIV are involved in the catalytic reaction. DPPIV-deficient mutants of P. gingivalis were constructed and subjected to animal experiments. Mice injected with the wild-type strain developed abscesses to a greater extent and died more frequently than those challenged with mutant strains. Mice injected with the mutants exhibited faster recovery from the infection, as assessed by weight gain and the rate of lesion healing. This decreased virulence of mutants compared with the parent strain suggests that DPPIV is a potential virulence factor of P. gingivalis and may play important roles in the pathogenesis of adult periodontitis induced by the organism.

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