PURIFICATION AND PROPERTIES OF STRICTOSIDINE SYNTHETASE (AN ENZYME CONDENSING TRYPTAMINE AND SECOLOGANIN) FROM CATHARANTHUS-ROSEUS CULTURED-CELLS

被引：57

作者：

MIZUKAMI, H ^{[1
]}

NORDLOV, H ^{[1
]}

LEE, SL ^{[1
]}

SCOTT, AI ^{[1
]}

机构：

[1] TEXAS A&M UNIV, DEPT CHEM, COLLEGE STN, TX 77843 USA

来源：

BIOCHEMISTRY | 1979年 / 18卷 / 17期

关键词：

D O I：

10.1021/bi00584a018

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

Strictosidine synthetase, which catalyzes the condensation of tryptamine with secologanin to form strictosidine (isovincoside), was purified 740-fold to homogeneity from cultured cells of C. roseus in 10% yield. The specific activity is 5.85 nkat/mg. The MW as estimated by gel filtration is 38,000. The isoelectric point is 4.6. Apparent Km values for tryptamine and secologanin are 0.83 and 0.46 mM, respectively. The enzyme shows a broad pH optimum between 5.0 and 7.5. The product of the enzymic reaction is exclusively strictosidine, while no trace of its epimer vincoside can be detected. Sulfhydryl inhibitors have no effect on the enzyme. End products in the biosynthetic pathway of indole alkaloids such as ajmalicine, vindoline and catharanthine do not inhibit the activity of strictosidine synthetase.

引用

页码：3760 / 3763

页数：4

共 28 条

[1] GEL-FILTRATION BEHAVIOUR OF PROTEINS RELATED TO THEIR MOLECULAR WEIGHTS OVER A WIDE RANGE [J].