血红蛋白与低分子量GTP结合蛋白ram p25之间可能的相互作用。

Possible interaction of haemoglobin with a low Mr GTP-binding protein, ram p25.

作者信息

Nagata K, Okano Y, Nozawa Y

机构信息

Department of Molecular Pathobiochemistry, Gifu University School of Medicine, Japan.

出版信息

Biochem Mol Biol Int. 1995 Mar;35(3):507-15.

PMID:7773187

Abstract

Haemoblobin (Hb) was observed to inhibit the GDP/GTP exchange activity of a low M(r) GTP-binding protein, ram p25. Hb also inhibited the [32P]GTP-hydrolysis activity of ram p25. These inhibitory effects of Hb were lost after incubation of Hb at 80 degrees C for 3 min, indicating that the ternary tetrameric structure of Hb is essential for the inhibitory effects on ram p25 activities. Hb did not inhibit [35S]GTP gamma S-binding of nucleotide-free ram p25. Methaemoglobin (MetHb) also inhibited both [3H]GDP-dissociation and [32P]GTP-hydrolysis activities of ram p25 in a very similar manner to Hb. The results strongly suggest that Hb may suppress physiological function(s) of ram p25 in vivo by inhibiting both [32P]GTP-hydrolysis and [3H]GDP-dissociation of ram p25.

摘要

观察到血红蛋白（Hb）可抑制低分子量GTP结合蛋白ram p25的GDP/GTP交换活性。Hb还抑制ram p25的[32P]GTP水解活性。在80℃孵育Hb 3分钟后，Hb的这些抑制作用消失，这表明Hb的三元四聚体结构对于其对ram p25活性的抑制作用至关重要。Hb不抑制无核苷酸ram p25的[35S]GTPγS结合。高铁血红蛋白（MetHb）也以与Hb非常相似的方式抑制ram p25的[3H]GDP解离和[32P]GTP水解活性。结果强烈表明，Hb可能通过抑制ram p25的[32P]GTP水解和[3H]GDP解离来抑制体内ram p25的生理功能。