{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,17]],"date-time":"2026-08-17T22:29:46Z","timestamp":1787005786892,"version":"build-2736575974"},"reference-count":0,"publisher":"National Academy of Sciences","issue":"18","content-domain":{"domain":["www.pnas.org"],"crossmark-restriction":true},"short-container-title":["Proc. Natl. Acad. Sci. U.S.A."],"published-print":{"date-parts":[[1989,9]]},"abstract":"<jats:p>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.<\/jats:p>","DOI":"10.1073\/pnas.86.18.6978","type":"journal-article","created":{"date-parts":[[2006,5,31]],"date-time":"2006-05-31T07:03:49Z","timestamp":1149059029000},"page":"6978-6981","update-policy":"https:\/\/doi.org\/10.1073\/pnas.cm10313","source":"Crossref","is-referenced-by-count":45,"title":["Mandelonitrile lyase from Ximenia americana L.: stereospecificity and lack of flavin prosthetic group."],"prefix":"10.1073","volume":"86","author":[{"given":"G W","family":"Kuroki","sequence":"first","affiliation":[{"name":"Department of Biochemistry and Biophysics, University of California, Davis 95616."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"E E","family":"Conn","sequence":"additional","affiliation":[{"name":"Department of Biochemistry and Biophysics, University of California, Davis 95616."}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"341","published-online":{"date-parts":[[1989,9]]},"container-title":["Proceedings of the National Academy of Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/pnas.org\/doi\/pdf\/10.1073\/pnas.86.18.6978","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,4,13]],"date-time":"2022-04-13T12:43:06Z","timestamp":1649853786000},"score":1,"resource":{"primary":{"URL":"https:\/\/pnas.org\/doi\/full\/10.1073\/pnas.86.18.6978"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1989,9]]},"references-count":0,"journal-issue":{"issue":"18","published-print":{"date-parts":[[1989,9]]}},"alternative-id":["10.1073\/pnas.86.18.6978"],"URL":"https:\/\/doi.org\/10.1073\/pnas.86.18.6978","relation":{},"ISSN":["0027-8424","1091-6490"],"issn-type":[{"value":"0027-8424","type":"print"},{"value":"1091-6490","type":"electronic"}],"subject":[],"published":{"date-parts":[[1989,9]]},"assertion":[{"value":"1989-09-01","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}