Promiscuous protease-catalyzed aldol reactions: a facile biocatalytic protocol for carbon-carbon bond formation in aqueous media.
Several proteases, especially pepsin, were observed to directly catalyze asymmetric aldol reactions. Pepsin, which displays well-documented proteolytic activity under acidic conditions, exhibited distinct catalytic activity in a crossed aldol reaction between acetone and 4-nitrobenzaldehyde with high yield and moderate enantioselectivity. Fluorescence experiments indicated that under neutral pH conditions, pepsin maintains its native conformation and that the natural structure plays an important role in biocatalytic promiscuity. Moreover, no significant loss of enantioselectivity was found even after four cycles of catalyst recycling, showing the high stability of pepsin under the selected aqueous reaction conditions. This case of biocatalytic promiscuity not only expands the application of proteases to new chemical transformations, but also could be developed into a potentially valuable method for green organic synthesis.
Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610064, PR China.
Chao
C
Li
Yu-Jie
YJ
Zhou
Na
N
Wang
Xing-Wen
XW
Feng
Kun
K
Li
Xiao-Qi
XQ
Yu
D000096:Acetone / Q000378:metabolism*; D001547:Benzaldehydes / Q000378:metabolism*; D001709:Biotechnology / Q000379:methods*; D002244:Carbon / Q000378:metabolism*; D002384:Catalysis; D015394:Molecular Structure; D010434:Pepsin A / Q000378:metabolism*; D011487:Protein Conformation; D013050:Spectrometry, Fluorescence; D014867:Water
D001547:Benzaldehydes; D014867:Water; D000096:Acetone; C029915:4-nitrobenzaldehyde; D002244:Carbon; D010434:Pepsin A