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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
2002-9-4
pubmed:abstractText
The metabolism of aldehydes and ketones in yeast is important for biosynthetic, catabolic and detoxication processes. Aldo-keto reductases are a family of enzymes that are able to reduce aldehydes and ketones. The roles of individual aldo-keto reductases in yeast has been difficult to determine because of overlapping substrate specificities of these enzymes. In this study, we have cloned, expressed and characterized the aldo-keto reductase Ypr1p from the yeast Saccharomyces cerevisiae and we describe its substrate specificity. The enzyme displays high specific activity towards 2-methylbutyraldehyde, as well as other aldehydes such as hexanal. It exhibits extremely low activity as a glycerol dehydrogenase. The enzyme functions over a wide pH range and uses NADPH as co-factor. In comparison to other mammalian and yeast aldo-keto reductases, Ypr1p has relatively high affinity for D,L-glyceraldehyde (1.08 mM) and hexanal (0.39 mM), but relatively low affinity for 4-nitrobenzaldehyde (1.07 mM). It displays higher specific activity for 2-methylbutyraldehyde than does yeast alcohol dehydrogenase and has a K(m) for 2-methyl butyraldehyde of 1.09 mM. The enzyme is expressed during growth on glucose, but its levels are rapidly induced by osmotic and oxidative stress. Yeast in which the YPR1 gene has been deleted possess 50% lower 2-methylbutyraldehyde reductase activity than the wild-type strain. This suggests that the enzyme may contribute to 2-methyl butyraldehyde reduction in vivo. It may therefore play a role in isoleucine catabolism and fusel alcohol formation and may influence flavour formation by strains of brewing yeast.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0749-503X
pubmed:author
pubmed:copyrightInfo
Copyright 2002 John Wiley & Sons, Ltd.
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
19
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1087-96
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Characterization of Ypr1p from Saccharomyces cerevisiae as a 2-methylbutyraldehyde reductase.
pubmed:affiliation
Department of Pharmaceutical Sciences, University of Strathclyde, 204 George Street, Glasgow G1 1XW, UK.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't