Subunit composition of hinokiresinol synthase controls enantiomeric selectivity in hinokiresinol formation.
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.
Yamamura
Masaomi
M
Research Institute for Sustainable Humanosphere, Kyoto University, Uji, Kyoto 611-0011, Japan.
Suzuki
Shiro
S
Hattori
Takefumi
T
Umezawa
Toshiaki
T
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
D017705:Lignans; D010636:Phenols; D021122:Protein Subunits; C119821:hinokiresinol; D008025:Ligases