To investigate the properties of wheat cytochrome P450 and the characteristics of herbicide metabolism by cytochrome P450 in vitro, deeply understand the mechanisms of herbicide selectivity, recombinant wheat cytochrome P450 monooxygenase (CYP71Cv1) heterologously expressed in yeast was purified by DE-52 cellulose chromatography and fast protein liquid chromatography (FPLC) with Mono-Q column. The degree of purification was 1366-fold. The specific activity of purified cytochrome P450 reached to 512 nmol min(-1) mg(-1) protein with herbicide chlorsulfuron as substrate. The purified cytochrome P450 exhibited one band in sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis, and the molecular mass was 52.5 kDa. Kinetic parameter was determined in vitro. The K-m values for chlorsulfuron and triasulfuron were 57 (+/-15) and 38 (+/-16) mu M, respectively; and V-max for chlorsulfuron and triasulfuron were 4.1 (+/-0.7) and 2.7 (+/-0.5) nmol min(-1) mg(-1) protein in vitro, respectively. (C) 2005 Elsevier Inc. All rights reserved.