诺氏疟原虫和雏鸭红细胞中的吡哆醇激酶

Pyridoxine kinase in Plasmodium lophurae and duckling erythrocytes.

作者信息

Platzer E G, Kassis J A

出版信息

J Protozool. 1978 Nov;25(4):556-9. doi: 10.1111/j.1550-7408.1978.tb04186.x.

DOI:10.1111/j.1550-7408.1978.tb04186.x

Abstract

Pyridoxine kinase enzyme activity was greatly increased in duckling erythrocytes infected with Plasmodium lophurae. Pyridoxine kinase activity in parasites freed from erythrocytes was much greater than that of uninfected erythrocytes. The apparent Km for pyridoxine of the parasite enzyme was 6.6 times 10(-5) M whereas the host red cell enzyme Km was 1.9 times 10(-6) M. Deoxypyridoxine inhibited host and parasite pyridoxine kinase activity with an apparent Ki of 1.5 times 10(-6) and 8.6 times 10(-6) M, respectively. These results suggest that the vitamin B6 metabolism of the malaria parasites is distinct and separate from that of the host erythrocytes.

摘要

感染了鸡疟原虫的雏鸭红细胞中，吡哆醇激酶的酶活性大幅增加。从红细胞中分离出的寄生虫中的吡哆醇激酶活性比未感染的红细胞高得多。寄生虫酶对吡哆醇的表观米氏常数为6.6×10⁻⁵M，而宿主红细胞酶的米氏常数为1.9×10⁻⁶M。脱氧吡哆醇抑制宿主和寄生虫的吡哆醇激酶活性，其表观抑制常数分别为1.5×10⁻⁶和8.6×10⁻⁶M。这些结果表明，疟原虫的维生素B6代谢与宿主红细胞的维生素B6代谢不同且相互独立。