title: Arabidopsis thaliana mitochondrial glyoxalase 2-1 exhibits beta-lactamase activity.
abstract: In an effort to determine the physiological role of Arabidopsis thaliana Glx2-1, we attempted to uncover a substrate for the enzyme. Glx2-1 did not effectively process 192 diverse substrates found in a commercial screen used for microorganism identification or exhibit arylsulfatase, lactonase, or phosphotriesterase activities. However, Glx2-1 does exhibit beta-lactamase activity with k(cat)/KM values from 10(3) to 10(5) M(-1) s(-1). Glx2-1 can hydrolyze cephalosporins and carbapenems, albeit with rate constants slower than those of most metallo-beta-lactamases. The potential role of a beta-lactamase in the mitochondria of plant cells is briefly discussed.
authors.affiliation: Department of Chemistry and Biochemistry, 160 Hughes Hall, 701 East High Street, Miami University, Oxford, Ohio 45056, USA.
authors.forename: Pattraranee
authors.initials: P
authors.lastname: Limphong
authors.forename: George
authors.initials: G
authors.lastname: Nimako
authors.forename: Pei W
authors.initials: PW
authors.lastname: Thomas
authors.forename: Walter
authors.initials: W
authors.lastname: Fast
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Makaroff
authors.forename: Michael W
authors.initials: MW
authors.lastname: Crowder
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000201:enzymology*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000378:metabolism*; D015780:Carbapenems / Q000378:metabolism; D002511:Cephalosporins / Q000378:metabolism; D006801:Humans; D006868:Hydrolysis; D007527:Isoenzymes / Q000737:chemistry / Q000378:metabolism; D008928:Mitochondria / Q000201:enzymology; D024101:Mitochondrial Proteins / Q000737:chemistry / Q000378:metabolism*; D008969:Molecular Sequence Data; D017510:Protein Folding; D013379:Substrate Specificity; D013869:Thiolester Hydrolases / Q000737:chemistry / Q000378:metabolism*; D001618:beta-Lactamases / Q000737:chemistry / Q000378:metabolism*; D000099301:Hydroxyacylglutathione Hydrolase
chemical_list: D029681:Arabidopsis Proteins; D015780:Carbapenems; D002511:Cephalosporins; D007527:Isoenzymes; D024101:Mitochondrial Proteins; D013869:Thiolester Hydrolases; D001618:beta-Lactamases; D000099301:Hydroxyacylglutathione Hydrolase