Publication Date:
1988-12-16
Description:
Three variations to the structure of the nicotinamide adenine dinucleotide (NAD)-dependent L-lactate dehydrogenase from Bacillus stearothermophilus were made to try to change the substrate specificity from lactate to malate: Asp197----Asn, Thr246----Gly, and Gln102----Arg). Each modification shifts the specificity from lactate to malate, although only the last (Gln102----Arg) provides an effective and highly specific catalyst for the new substrate. This synthetic enzyme has a ratio of catalytic rate (kcat) to Michaelis constant (Km) for oxaloacetate of 4.2 x 10(6)M-1 s-1, equal to that of native lactate dehydrogenase for its natural substrate, pyruvate, and a maximum velocity (250 s-1), which is double that reported for a natural malate dehydrogenase from B. stearothermophilus.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Wilks, H M -- Hart, K W -- Feeney, R -- Dunn, C R -- Muirhead, H -- Chia, W N -- Barstow, D A -- Atkinson, T -- Clarke, A R -- Holbrook, J J -- New York, N.Y. -- Science. 1988 Dec 16;242(4885):1541-4.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biochemistry, University of Bristol, United Kingdom.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/3201242" target="_blank"〉PubMed〈/a〉
Keywords:
Binding Sites
;
Geobacillus stearothermophilus/*enzymology/genetics
;
Kinetics
;
L-Lactate Dehydrogenase/*genetics/metabolism
;
Malate Dehydrogenase/*metabolism
;
Models, Molecular
;
Protein Conformation
;
Substrate Specificity
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
