STEREOSELECTIVITY OF MICROBIAL LIPASES - THE SUBSTITUTION AT POSITIONSN-2 OF TRIACYLGLYCEROL ANALOGS INFLUENCES THE STEREOSELECTIVITY OF DIFFERENT MICROBIAL LIPASES

Citation
P. Stadler et al., STEREOSELECTIVITY OF MICROBIAL LIPASES - THE SUBSTITUTION AT POSITIONSN-2 OF TRIACYLGLYCEROL ANALOGS INFLUENCES THE STEREOSELECTIVITY OF DIFFERENT MICROBIAL LIPASES, European journal of biochemistry, 227(1-2), 1995, pp. 335-343
Citations number
47
Categorie Soggetti
Biology
ISSN journal
00142956
Volume
227
Issue
1-2
Year of publication
1995
Pages
335 - 343
Database
ISI
SICI code
0014-2956(1995)227:1-2<335:SOML-T>2.0.ZU;2-V
Abstract
In the present study, the stereoselectivity of purified lipases from C andida rugosa, Chromobacterium viscosum, Pseudomonas species and Rhizo pus arrhizus towards triacylglycerols in comparison to various structu ral analogs were investigated. Different triacylglycerol analogs with distinct polarities at position sn-2 of the glycerol backbone (1,3-dia cyl-2-X-glycerol, where 2-X = 2-acyloxy, 2-alkyloxy, 2-deoxy-2-alkyl, or 2-deoxy-2-phenyl) were synthesized. Substrate hydrophobicity and st eric requirement was modified by variation of the alkyl and acyl chain length. Hydrolysis of these substrates demonstrated that minor struct ural variations at C2 of triacylglycerol strongly affect the stereosel ectivity of the lipases tested. It was noteworthy that the variation o f substrate structure did not only affect the quantity of stereoselect ivity expressed as percentage enantiomeric excess, but also resulted i n a reversal of stereo-preference in some cases. Replacement of the ac ylester in position 2 of glycerol by a non-ester-linked aliphatic moie ty shifted the preference of Chromobacterium viscosum lipase from sn-3 to sn-1. Lipases from Chromobacterium viscosum, Pseudomonas species a nd Rhizopus arrhizus exhibited sn-3 preference with 2-deoxy-2-phenyl a nalogs, while towards substrates with a 2-deoxy-2-alkyl moiety sn-1 st ereobias was recorded. Candida rugosa lipase was rather insensitive to substrate variations concerning the polarity at position 2 of the gly cerol backbone. However, variation of the acyl chain length significan tly influenced stereoselectivity of this lipase.