Genetic Epidemiology, Translational Neurogenomics, Psychiatric Genetics and Statistical Genetics Laboratories investigate the pattern of disease in families, particularly identical and non-identical twins, to assess the relative importance of genes and environment in a variety of important health problems.
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PMID
15450854
TITLE
Esterase catalysis of substrate vapour: enzyme activity occurs at very low hydration.
ABSTRACT
It has been generally accepted that enzyme activity requires a minimal hydration of about 0.2 g H2O g(-1) protein. This fits well with evidence that hydration above this level is associated with the onset of intramolecular motions. The influence of enzyme hydration on the hydrolysis of substrate by Candida rugosa Lipase B and pig liver esterase was investigated. Each enzyme was studied as a powder at various hydration levels, using vapour phase ethyl butyrate as substrate. This procedure allows the separation of those effects that are due to hydration from those arising from diffusional constraints. We found hydrolytic activity in both enzymes at all hydration levels above zero (between 0.054-0.47 and 0.029-0.60 g H2O g(-1) protein, respectively) that were investigated. The lowest hydration level investigated, <0.03 g H2O g(-1) enzyme, corresponded to a water/enzyme mole ratio of 100 and a coverage of about 10% of the enzyme surface by water molecules. The hydrolytic activity of both enzymes was dependent on protein hydration. However, since the hydrolysis of ethyl butyrate requires water as a second substrate, the absence of activity at zero hydration does not rule out the possibility of enzyme activity in the absence of water. These results suggest that the properties conferred on proteins by water, at least above 10% surface coverage (in this case corresponding to a hydration level of 0.03 g H2O g(-1) protein), are not a requirement for enzyme catalysis.
DATE PUBLISHED
2004 Oct 1
HISTORY
PUBSTATUS PUBSTATUSDATE
pubmed 2004/09/29 05:00
medline 2004/11/02 09:00
received 2004/00/22
accepted 2004/00/11
entrez 2004/09/29 05:00
AUTHORS
NAME COLLECTIVENAME LASTNAME FORENAME INITIALS AFFILIATION AFFILIATIONINFO
Lind PA Lind Penelope A PA Department of Genetics, University of North Carolina, Chapel Hill, NC 27599, USA.
Daniel RM Daniel Roy M RM
Monk C Monk Colin C
Dunn RV Dunn Rachel V RV
INVESTIGATORS
JOURNAL
VOLUME: 1702
ISSUE: 1
TITLE: Biochimica et biophysica acta
ISOABBREVIATION: Biochim. Biophys. Acta
YEAR: 2004
MONTH: Oct
DAY: 1
MEDLINEDATE:
SEASON:
CITEDMEDIUM: Print
ISSN: 0006-3002
ISSNTYPE: Print
MEDLINE JOURNAL
MEDLINETA: Biochim Biophys Acta
COUNTRY: Netherlands
ISSNLINKING: 0006-3002
NLMUNIQUEID: 0217513
PUBLICATION TYPE
PUBLICATIONTYPE TEXT
Journal Article
Research Support, Non-U.S. Gov't
COMMENTS AND CORRECTIONS
GRANTS
GENERAL NOTE
KEYWORDS
MESH HEADINGS
DESCRIPTORNAME QUALIFIERNAME
Animals
Butyrates metabolism
Candida enzymology
Catalysis enzymology
Esterases metabolism
In Vitro Techniques metabolism
Kinetics metabolism
Lipase metabolism
Liver enzymology
Substrate Specificity enzymology
Sus scrofa enzymology
Water chemistry
SUPPLEMENTARY MESH
GENE SYMBOLS
CHEMICALS
REGISTRYNUMBER NAMEOFSUBSTANCE
0 Butyrates
059QF0KO0R Water
EC 3.1.- Esterases
EC 3.1.1.3 Lipase
UFD2LZ005D ethyl butyrate
OTHER ID's