梨形四膜虫中的镁敏感鸟苷酸环化酶及其内源性激活因子。

Magnesium-sensitive guanylate cyclase and its endogenous activating factor in Tetrahymena pyriformis.

作者信息

Nakazawa K, Shimonaka H, Nagao S, Kudo S, Nozawa Y

出版信息

J Biochem. 1979 Aug;86(2):321-4. doi: 10.1093/oxfordjournals.jbchem.a132529.

DOI:10.1093/oxfordjournals.jbchem.a132529

Abstract

Guanylate cyclase [EC 4.6.1.2] activity in Tetrahymena pyriformis cells was associated with particulate fractions, but not with soluble fractions. Mg2+ was much more effective than Mn2+ in activating the cyclase activity. Both specific and total cyclase activities with Mg2+ in the particulate fraction were very much lower than those in the original homogenate. The addition of the soluble fraction resulted in a marked enhancement of the particulate-bound cyclase activity, while the adenylate cyclase [EC 4.6.1.1] activity was not enhanced. The enhancement was dependent on Ca2+, and the activating factor is suggested to be a protein.

摘要

梨形四膜虫细胞中的鸟苷酸环化酶[EC 4.6.1.2]活性与颗粒部分相关，而与可溶性部分无关。Mg2+在激活环化酶活性方面比Mn2+有效得多。颗粒部分中Mg2+存在时的比活性和总环化酶活性均远低于原始匀浆中的活性。添加可溶性部分导致颗粒结合的环化酶活性显著增强，而腺苷酸环化酶[EC 4.6.1.1]活性未增强。这种增强依赖于Ca2+，并且激活因子被认为是一种蛋白质。