Linked Life Data

2780553

Source:http://linkedlifedata.com/resource/pubmed/id/2780553

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
18
pubmed:dateCreated
1989-10-24
pubmed:abstractText
A mandelonitrile lyase (EC 4.1.2.10) that catalyzes the dissociation of (S)-(-)-mandelonitrile to benzaldehyde and hydrogen cyanide has been purified to apparent homogeneity from leaves of Ximenia americana L. (Olacaceae). The lyase was purified 122-fold with 38% yield by chromatography on carboxymethyl-cellulose and chromatofocusing. The enzyme had a pH optimum of 5.5, with a Km value of 280 microM. Activity toward 4-hydroxy-(R,S)-mandelonitrile was 77% of that observed with the endogenous substrate; no activity was observed toward the aliphatic substrate acetone cyanohydrin. The enzyme was stable at 4 degrees C and at room temperature for at least 1 month. Native and subunit molecular weights of 38,000 and 36,500, respectively, suggest the enzyme is a monomer. The isoelectric point was pH 3.9 as determined by isoelectric focusing. Staining with periodic acid-Schiff and fluorescein-labeled concanavalin A reagents indicate this enzyme is a glycoprotein. In contrast to (R)-mandelonitrile lyases isolated from Prunus species, the Ximenia lyase does not appear to be a flavoprotein. A second enzyme that eluted from the chromatofocusing column at pH 4.0 was also active toward mandelonitrile. However, this form accounted for less than 10% of the total activity, and its specific activity was only 6% of that of the major component. Additional physical and kinetic studies suggested this activity may be due to a nonspecific enzyme that is active toward mandelonitrile.
pubmed:grant
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/2780553-1213680, http://linkedlifedata.com/resource/pubmed/commentcorrection/2780553-13970146, http://linkedlifedata.com/resource/pubmed/commentcorrection/2780553-3377504, http://linkedlifedata.com/resource/pubmed/commentcorrection/2780553-3674409, http://linkedlifedata.com/resource/pubmed/commentcorrection/2780553-3717954, http://linkedlifedata.com/resource/pubmed/commentcorrection/2780553-3777939, http://linkedlifedata.com/resource/pubmed/commentcorrection/2780553-3967669, http://linkedlifedata.com/resource/pubmed/commentcorrection/2780553-4623885, http://linkedlifedata.com/resource/pubmed/commentcorrection/2780553-4988336, http://linkedlifedata.com/resource/pubmed/commentcorrection/2780553-500702, http://linkedlifedata.com/resource/pubmed/commentcorrection/2780553-5432063, http://linkedlifedata.com/resource/pubmed/commentcorrection/2780553-5922969, http://linkedlifedata.com/resource/pubmed/commentcorrection/2780553-6161559, http://linkedlifedata.com/resource/pubmed/commentcorrection/2780553-6697988, http://linkedlifedata.com/resource/pubmed/commentcorrection/2780553-6721681
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0027-8424
pubmed:author
pubmed:issnType
Print
pubmed:volume
86
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
6978-81
pubmed:dateRevised
2009-11-18
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
Mandelonitrile lyase from Ximenia americana L.: stereospecificity and lack of flavin prosthetic group.
pubmed:affiliation
Department of Biochemistry and Biophysics, University of California, Davis 95616.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.