Lipases from Rhizomucor miehei and Humicola lanuginosa: Modification of the lid covering the active site alters enantioselectivity
1993 (English)In: Journal of Protein Chemistry, ISSN 02778033 (ISSN), Vol. 12, no 6, 749-757 p.Article in journal (Refereed) Published
The homologous lipases from Rhizomucor miehei and Humicola lanuginosa showed approximately the same enantioselectivity when 2-methyldecanoic acid esters were used as substrates. Both lipases preferentially hydrolyzed the S- enantiomer of 1-heptyl 2-methyldecanoate (R. miehei: E(S) = 8.5; H. lanuginosa: E(S) = 10.5), but the R-enantiomer of phenyl 2-methyldecanoate (E(R) = 2.9). Chemical arginine specific modification of the R. miehei lipase with 1,2-cyclohexanedione resulted in a decreased enantioselectivity (E(R) = 2.0), only when the phenyl ester was used as a substrate. In contrast, treatment with phenylglyoxal showed a decreased enantioselectivity (E(S) = 2.5) only when the heptyl ester was used as a substrate. The presence of guanidine, an arginine side chain analog, decreased the enantioselectivity with the heptyl ester (E(S) = 1.9) and increased the enantioselectivity with the aromatic ester (E(R) = 4.4) as substrates. The mutation, Glu 87 Ala, in the lid of the H. lanuginosa lipase, which might decrease the electrostatic stabilization of the open-lid conformation of the lipase, resulted in 47% activity compared to the native lipase, in a tributyrin assay. The Glu 87 Ala mutant showed an increased enantioselectivity with the heptyl ester (E(S) = 17.4) and a decreased enantioselectivity with the phenyl ester (E(R) = 2.5) as substrates, compared to native lipase. The enantioselectivities of both lipases in the esterification of 2-methyldecanoic acid with 1-heptanol were unaffected by the lid modifications.
Place, publisher, year, edition, pages
1993. Vol. 12, no 6, 749-757 p.
alanine, arginine, decanoic acid derivative, ester, guanidine, heptanol, phenylglyoxal, triacylglycerol lipase, article, chemical modification, enantiomer, enzyme activation, enzyme active site, enzyme conformation, enzyme substrate, esterification, gas chromatography, hydrolysis, lipid metabolism, nonhuman, site directed mutagenesis, Comparative Study, Cyclohexanones, Decanoates, Enzymes, Immobilized, Kinetics, Lipase, Mitosporic Fungi, Mucorales, Stereoisomerism, Substrate Specificity, Support, Non-U.S. Gov't, Humicola, Rhizomucor miehei, Thermomyces lanuginosus
IdentifiersURN: urn:nbn:se:kth:diva-74874DOI: 10.1007/BF01024933OAI: oai:DiVA.org:kth-74874DiVA: diva2:490138
Chemicals/CAS: 1,2-cyclohexanedione, 765-87-7; Arginine, 74-79-3; Cyclohexanones; Decanoates; Enzymes, Immobilized; Lipase, EC 126.96.36.199; Phenylglyoxal, 1074-12-0 NR 201408052012-02-032012-02-032012-02-03Bibliographically approved