| Literature DB >> 13678276 |
Nobuko Hano1, Yumiko Nakashima, Kyoko Shinzawa-Itoh, Shinya Yoshikawa.
Abstract
Steady state kinetics of bovine heart NADH: coenzyme Q oxidoreductase using coenzyme Q with two isoprenoid unit (Q2) or with a decyl group (DQ) show an ordered sequential mechanism in which the order of substrate binding and product release is NADH-Q2 (DQ) -Q2H2 (DQH2)-NAD+ in contrast to the order determined using Q1 (Q1-NADH-NAD(+)-Q1H2) (Nakashima et al., J. Bioenerg. Biomembr. 34, 11-19, 2002). The effect of the side chain structure of coenzyme Q suggests that NADH binding to the enzyme results in a conformational change, in the coenzyme Q binding site, which enables the site to accept coenzyme Q with a side chain significantly larger than one isoprenoid unit. The side chains of Q2 and DQ bound to the enzyme induce a conformational change in the binding site to stabilize the substrate binding, while the side chain of Q1 (one isoprenoid unit) is too short to induce the conformational change.Entities:
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Year: 2003 PMID： 13678276 DOI： 10.1023/a:1024663715931
Source DB: PubMed Journal: J Bioenerg Biomembr ISSN： 0145-479X Impact factor: 2.945