Coenzyme Activity of NAD Analogs for 3-Isopropylmalate Dehydrogenase from Thermus thermophilus HB8

A Chiba; T Eguchi; T Oshima; K Kakinuma

doi:10.1271/bbb.63.1647

Coenzyme Activity of NAD Analogs for 3-Isopropylmalate Dehydrogenase from Thermus thermophilus HB8

Biosci Biotechnol Biochem. 1999;63(9):1647-9. doi: 10.1271/bbb.63.1647.

Authors

A Chiba¹, T Eguchi², T Oshima³, K Kakinuma¹

Affiliations

¹ a Department of Chemistry, Tokyo Institute of Technology.
² b Department of Chemistry and Materials Science, Tokyo Institute of Technology.
³ c School of Life Science, Tokyo University of Pharmacy and Life Science.

PMID: 27389650
DOI: 10.1271/bbb.63.1647

Abstract

In order to elucidate the enzyme-substrate-cofactor interaction in 3-isopropylmalate dehydrogenase, the coenzyme activity of NAD analogs which have a 3-substituted pyridine ring was examined. Analogs 3-5 showed diminished k cat values compared with those of NAD(+), whereas thiocarboxamide 2 was almost as equally active as NAD(+). This suggests that the NH2 functionality of NAD(+) is more important for the catalysis of IPMDH than a carbonyl group.

Keywords: 3-isopropylmalate dehydrogenase; NAD analog; Thermus thermophilus HB8; coenzyme activity.