Category Ranking
98%
Total Visits
921
Avg Visit Duration
2 minutes
Citations
20
Article Abstract
An open reading frame of 1100 bp in the partially sequenced genome sequence of alkaliphilic Bacillus pseudofirmus OF4 was identified as a putative alanine racemase gene (dadX(OF4)), which was cloned and expressed in Escherichia coli BL21 (DE3). The encoded protein DadX(OF4) was purified to homogeneity by His(6)-tag affinity column, gel filtration and ion-exchange chromatography. The amino acid sequence has highest identity with the known alanine racemase from Oceanobacillus iheyensis HTE831 (48%). The protein was a dimeric, endogenous PLP-dependent enzyme, which was demonstrated by absorption spectra and enzyme activity with or without PLP. The racemization temperature optimum was 40 degrees C and the optimal pH was 10.5. The kinetic parameters K(m) and V(max) at 40 degrees C of alanine racemase, determined by HPLC analysis, were 41.79 mM, 10,500 units/mg for L-alanine and 14.91 mM, 3708 units/mg for D-alanine, respectively.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/j.jbiosc.2008.11.005 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
A D-alanine aminotransferase SF substitution confers resistance to β-chloro-D-alanine in via antibiotic inactivation.
bioRxiv
August 2025
Microbiology, School of Biological and Chemical Sciences, University of Galway, Ireland.
Alanine transport and metabolism impact MRSA pathophysiology by dictating the availability of d-alanine for cell wall synthesis, the target of β-lactam antibiotics. Furthermore -dependent alanine transport controls MRSA β-lactam susceptibility in chemically defined medium (CDM) in a glucose-dependent manner. Here we report that was auxotrophic for l-alanine in CDM, and that this growth defect was rescued by glucose (or compensatory mutations), but only when the alanine racemase () and d-alanine aminotransferase () genes were functional.
View Article and Find Full Text PDFD-Alanine content in the marine edible bivalve Panopea japonica and evaluation of its associated enzyme activities.
Sci Rep
July 2025
Department of Analytical Chemistry, Faculty of Pharmaceutical Sciences, Toho University, 2-2-1 Miyama, Funabashi-shi, 274-8510, Chiba, Japan.
Amino acids play essential roles in various biological processes. In humans, most amino acids are present in the L-form; however, small amounts of D-amino acids also exist and have significant physiological roles, highlighting the importance of dietary intake from foods or drinks. In this study, we investigated the amino acid composition of the geoduck clam Panopea japonica, emphasizing its remarkably high D-alanine (D-Ala) content in the siphon tissue.
View Article and Find Full Text PDFD-alanine synthesis and exogenous alanine affect the antimicrobial susceptibility of .
Antimicrob Agents Chemother
July 2025
Department of Bacteriology, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan.
D-alanine is an important amino acid for peptidoglycan biosynthesis in . In addition, D-alanine is used for the modification of teichoic acids to weaken the net surface negative charge, leading to decreased susceptibility to cationic antimicrobial agents. D-alanine synthesis is dependent on only two enzymes.
View Article and Find Full Text PDFElucidation of multifunctionality and substrate specificity of human aspartate aminotransferases.
Biochim Biophys Acta Proteins Proteom
September 2025
Graduate School of Pharmaceutical Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan; School of Pharmacy, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan.
d-Serine and d-aspartate play crucial physiological roles in mammals. d-Serine is produced by serine racemase, but the biosynthetic pathway of d-aspartate remains unclear. In this study, we investigated the substrate specificity and multifunctionality of human aspartate aminotransferases (hGOT1 and hGOT2) to reveal whether they possess d-Amino acid metabolic activity.
View Article and Find Full Text PDFThe Isolation, Structural Characterization, and Biosynthetic Pathway of Unguisin from the Marine-Derived Fungus .
Mar Drugs
May 2025
Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China.
Unguisins, a class of structurally complex cyclic peptides featuring a -aminobutyric acid residue embedded in the skeleton, exhibit diverse biological activities. Here, a new unguisin K, along with three known congeners, was isolated from the marine-derived fungus MEFC1001. The biosynthetic pathway was elucidated through gene disruption coupled with in vitro enzymatic characterization.
View Article and Find Full Text PDF