野生型和耐霉酚酸胎儿三毛滴虫中的嘌呤碱转运

Purine base transport in wild-type and mycophenolic acid-resistant Tritrichomonas foetus.

作者信息

Hedstrom L, Wang C C

机构信息

Department of Pharmaceutical Chemistry, School of Pharmacy, University of California, San Francisco.

出版信息

Mol Biochem Parasitol. 1989 Jul;35(3):219-27. doi: 10.1016/0166-6851(89)90208-9.

DOI:10.1016/0166-6851(89)90208-9

PMID:2747744

Abstract

The purine base transport systems of wild-type and mycophenolic acid-resistant (MPAR) Tritrichomonas foetus have been characterized. Wild-type T. foetus has two carriers, one for hypoxanthine (Km = 0.7 +/- 0.3 mM, Vm = 80 +/- 20 pmol microliters-1min-1) and guanine (Km = 0.09 +/- 0.02 mM, Vm = 17 +/- 3 pmol microliters-1min-1), and a second for xanthine (Km = 0.6 +/- 0.2 mM, Vm = 25 +/- 5 pmol microliters-1min-1). Adenine transport was not saturable (k = 0.16 +/- 0.01 min-1) and therefore appears to enter the parasite by passive diffusion through the membrane. T. foetus MPAR has lost the hypoxanthine/guanine transporter. Xanthine and adenine transport are similar in wild-type and MPAR T. foetus. No purine nucleoside transporter could be identified.

摘要

已对野生型和耐霉酚酸（MPAR）胎儿三毛滴虫的嘌呤碱转运系统进行了表征。野生型胎儿三毛滴虫有两种载体，一种用于次黄嘌呤（Km = 0.7 +/- 0.3 mM，Vm = 80 +/- 20 pmol微升-1分钟-1）和鸟嘌呤（Km = 0.09 +/- 0.02 mM，Vm = 17 +/- 3 pmol微升-1分钟-1），另一种用于黄嘌呤（Km = 0.6 +/- 0.2 mM，Vm = 25 +/- 5 pmol微升-1分钟-1）。腺嘌呤转运不饱和（k = 0.16 +/- 0.01分钟-1），因此似乎通过被动扩散穿过膜进入寄生虫。胎儿三毛滴虫MPAR已失去次黄嘌呤/鸟嘌呤转运体。野生型和MPAR胎儿三毛滴虫中的黄嘌呤和腺嘌呤转运相似。未鉴定出嘌呤核苷转运体。