LIPOXYGENATION ACTIVITY OF PURIFIED PROSTAGLANDIN-FORMING CYCLOOXYGENASE

被引：86

作者：

HEMLER, ME ^{[1
]}

CRAWFORD, CG ^{[1
]}

LANDS, WEM ^{[1
]}

机构：

[1] UNIV MICHIGAN,DEPT BIOL CHEM,ANN ARBOR,MI 48109

来源：

BIOCHEMISTRY | 1978年 / 17卷 / 09期

关键词：

D O I：

10.1021/bi00602a031

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：

Purified cyclooxygenase, a single enzyme which catalyzes the formation of endoperoxide from arachidonic acid (20:4) in a bis (dioxygenase) reaction, is capable of oxygenating eicosadienoic acid (20:2) at C-11 in a single dioxygenase reaction. The partial oxygenation of 20:2 resembles the formation of prostaglandin from 20:4, with both oxygenation reactions exhibiting similar pH optima, substrate Km values, and cofactor effects including a need for peroxide and an absolute requirement for heme. In addition, those processes known to destroy 20:4 oxygenase activity, such as heat inactivation, inactivation with anti-inflammatory drugs, and turnover-mediated inactivation, have equally destructive effects on 20:2 oxygenase activity. Thus, both oxygenations are catalyzed by one enzyme. All of the above similarities for 20:2 and 20:4 oxygenation demonstrate that C-l 1 oxygenation is an integral rate-limiting step of cyclooxygenase action rather than a separate reaction resembling that of plant lipoxygenase. © 1978, American Chemical Society. All rights reserved.

引用

页码：1772 / 1779

页数：8

共 48 条

[1]

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[2]

BORGEAT P, 1976, J BIOL CHEM, V251, P7816

[3] SOYBEAN LIPOXYGENASE - IRON-CONTAINING DIOXYGENASE [J].