Effects of Macromolecular Crowding on Alcohol Dehydrogenase Activity Are Substrate-Dependent.

Content Provider	Semantic Scholar
Author	Wilcox, Alicia LoConte, Micaela A. Slade, Kristin M.
Copyright Year	2016
Abstract	Enzymes operate in a densely packed cellular environment that rarely matches the dilute conditions under which they are studied. To better understand the ramifications of this crowding, the Michaelis-Menten kinetics of yeast alcohol dehydrogenase (YADH) were monitored spectrophotometrically in the presence of high concentrations of dextran. Crowding decreased the maximal rate of the reaction by 40% for assays with ethanol, the primary substrate of YADH. This observation was attributed to slowed release of the reduced β-nicotinamide adenine dinucleotide product, which is rate-limiting. In contrast, when larger alcohols were used as the YADH substrate, the rate-limiting step becomes hydride transfer and crowding instead increased the maximal rate of the reaction by 20-40%. This work reveals the importance of considering enzyme mechanism when evaluating the ways in which crowding can alter kinetics.
Starting Page	2125
Ending Page	2129
Page Count	5
File Format	PDF HTM / HTML
Alternate Webpage(s)	http://wxjs.chinayyhg.com/upload/Files/20160909234139393/3550-3558.pdf
PubMed reference number	27283046v1
Alternate Webpage(s)	https://doi.org/10.1021/acs.biochem.6b00257
DOI	10.1021/acs.biochem.6b00257
Journal	Biochemistry
Volume Number	55
Issue Number	25
Language	English
Access Restriction	Open
Subject Keyword	Adenine Alcohol dehydrogenase Alcohols Dextrans Dinucleoside Phosphates Ethanol 0.62 ML/ML Topical Gel Large NADP Pack unit
Content Type	Text
Resource Type	Article