title: Subunit composition of hinokiresinol synthase controls enantiomeric selectivity in hinokiresinol formation.
abstract: Asparagus officinalis hinokiresinol synthase (HRS) is composed of two subunits, HRSalpha and HRSbeta. Individually, each subunit forms (E)-hinokiresinol (EHR) from 4-coumaryl 4-coumarate, whereas a mixture of both subunits forms (Z)-hinokiresinol (ZHR) from the same substrate. In this study, we analyzed the enantiomeric compositions of ZHR and EHR formed after incubation of 4-coumaryl 4-coumarate with recombinant subunit proteins, recHRSalpha and/or recHRSbeta, and with naturally occurring A. officinalis ZHR. The enantiomeric composition of ZHR formed by the mixture of recHRSalpha and recHRSbeta was (+)-100% enantiomer excess (e.e.), identical to that of A. officinalis ZHR. In contrast, the enantiomeric compositions of EHR formed by recHRSalpha and recHRSbeta, individually, were (-)-20.6 and (-)-9.0% e.e., respectively. These results clearly demonstrate that the subunit composition of A. officinalis HRS controls not only cis/trans isomerism but also enantioselectivity in hinokiresinol formation.
authors.affiliation: Research Institute for Sustainable Humanosphere, Kyoto University, Uji, Kyoto 611-0011, Japan.
authors.forename: Masaomi
authors.initials: M
authors.lastname: Yamamura
authors.forename: Shiro
authors.initials: S
authors.lastname: Suzuki
authors.forename: Takefumi
authors.initials: T
authors.lastname: Hattori
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Umezawa
mesh_terms: D027761:Asparagus Plant / Q000201:enzymology*; D007536:Isomerism; D008025:Ligases / Q000737:chemistry / Q000378:metabolism*; D017705:Lignans / Q000378:metabolism*; D010636:Phenols / Q000378:metabolism*; D021122:Protein Subunits / Q000737:chemistry / Q000378:metabolism
chemical_list: D017705:Lignans; D010636:Phenols; D021122:Protein Subunits; C119821:hinokiresinol; D008025:Ligases