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Reaction selectivity of rhizomucor miehei lipase as influenced by monoacylation of sn ‐glycerol
Author(s) -
Fu Xun,
Parkin Kirk L.
Publication year - 2004
Publication title -
journal of the american oil chemists' society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.512
H-Index - 117
eISSN - 1558-9331
pISSN - 0003-021X
DOI - 10.1007/s11746-004-0856-0
Subject(s) - rhizomucor miehei , selectivity , chemistry , lipase , glycerol , substrate (aquarium) , stereochemistry , triacylglycerol lipase , enzyme , organic chemistry , catalysis , biology , ecology
Reaction selectivities were determined in multicompetitive reactions mediated by Rhizomucor miehei (RM) lipase at water activity of 0.19 in hexane. Saturated FA (C4–C18 even chain) and oleic acid (C18∶1) were reacted with a single alcohol, glycerol, or α‐or β‐MAG containing C4, C10, C16, or C18∶1 individually as alcohol cosubstrate. Similar patterns of broad FA selectivity toward C8–C18 FA were generally observed for esterification into specific acylglycerol (AG) pools with the different α/β‐CX‐MAG cosubstrates. Exceptions were enrichment of C18 in the MAG pool with α‐C16‐MAG substrate, and a general suppression of C4/C6 FA reactivity and a specific discrimination toward >C8 FA incorporation into the TAG pool, both for reactions with α‐C10‐ and α‐C16‐MAG. RM lipase selectivity toward MAG was in descending order: β‐C18∶1‐MAG>α/β‐C4‐MAG∼β‐C10‐MAG∼β‐C16‐MAG>α‐C18∶1‐MAG >α‐C10‐MAG∼α‐C16‐MAG. Selectivity in channeling CX of the original CX‐MAG substrates into higher AG species was in descending order: α‐C10‐MAG∼α‐C16‐MAG>β‐C10‐MAGβ‐C16‐MAG>α‐C18∶1‐MAG>β‐C18∶1‐MAG∼ α/β‐C4‐MAG. Aside from their characteristic FA selectivity, Burkholderia cepacia (PS‐30) and RM lipases behaved similarly in terms of MAG selectivity as well as a general conservation of FA selectivity throughout the sequential steps of TAG assembly from FA and glycerol for processes designed to yield specifically structured TAG.