碱性多肽对植物钙依赖性蛋白激酶的抑制作用。

Inhibition of plant calcium-dependent protein kinases by basic polypeptides.

作者信息

Polya G M, Nott R, Klucis E, Minichiello J, Chandra S

机构信息

Department of Biochemistry, La Trobe University, Bundoora, Victoria, Australia.

出版信息

Biochim Biophys Acta. 1990 Feb 9;1037(2):259-62. doi: 10.1016/0167-4838(90)90177-h.

DOI:10.1016/0167-4838(90)90177-h

PMID:2306477

Abstract

Wheat embryo Ca2+-dependent protein kinase (CDPK) is inhibited by a variety of polypeptides including actin, gramicidin S, melittin, protamine, various histone preparations, histone H4 and by basic amino-acid homopolymers. Melittin (Ki 9 microM) is a non-competitive inhibitor of wheat germ CDPK and also inhibits wheat leaf CDPK and silver beet leaf CDPKs. Protamine inhibits wheat germ CDPK in an apparently competitive fashion (Ki 0.2 microM) and is also a potent, albeit less effective, inhibitor of the leaf CDPKs. Various basic amino-acid homopolymers are also potent, apparently competitive inhibitors of wheat embryo CDPK, namely poly(L-lysine) (IC50 2 nM), poly(L-ornithine) (IC50 3 nM) and poly(L-arginine) (IC50 17 nM) and also inhibit the leaf CDPKs, albeit at higher concentrations. Histone H4 and various calf thymus histone preparations inhibit wheat embryo CDPK in a fashion that is not competitive and calmodulin can substantially reverse such inhibition.

摘要

小麦胚钙依赖蛋白激酶（CDPK）受到多种多肽的抑制，包括肌动蛋白、短杆菌肽S、蜂毒肽、鱼精蛋白、各种组蛋白制剂、组蛋白H4以及碱性氨基酸同聚物。蜂毒肽（Ki为9微摩尔）是小麦胚CDPK的非竞争性抑制剂，也能抑制小麦叶片CDPK和瑞士甜菜叶片CDPK。鱼精蛋白以明显的竞争性方式抑制小麦胚CDPK（Ki为0.2微摩尔），并且也是叶片CDPK的有效抑制剂，尽管效果稍差。各种碱性氨基酸同聚物也是小麦胚CDPK的有效、明显竞争性抑制剂，即聚（L-赖氨酸）（IC50为2纳摩尔）、聚（L-鸟氨酸）（IC50为3纳摩尔）和聚（L-精氨酸）（IC50为17纳摩尔），它们也能抑制叶片CDPK，尽管所需浓度较高。组蛋白H4和各种小牛胸腺组蛋白制剂以非竞争性方式抑制小麦胚CDPK，而钙调蛋白可显著逆转这种抑制作用。