鸟嘌呤核苷酸结合蛋白在植物下胚轴微粒体组分中的存在。

Presence of guanine nucleotide-binding proteins in a plant hypocotyl microsomal fraction.

作者信息

Drobak B K, Allan E F, Comerford J G, Roberts K, Dawson A P

机构信息

John Innes Institute, Norwich, England.

出版信息

Biochem Biophys Res Commun. 1988 Feb 15;150(3):899-903. doi: 10.1016/0006-291x(88)90713-9.

DOI:10.1016/0006-291x(88)90713-9

PMID:3124845

Abstract

The presence of specific guanine nucleotide-binding proteins in a zucchini (Cucurbita pepo L.) hypocotyl microsomal fraction was investigated. Polypeptides were separated by sodium dodecyl sulphate polyacrylamide gel electrophoresis and transferred to nitrocellulose. Incubation of nitrocellulose blots with [alpha-32P]GTP and [gamma-32P]GTP indicated the presence of four specific and distinct GTP-binding proteins with molecular masses of approx. 23.4 kDa, 24.8 kDa, 26.6 kDa and 28.5 kDa. Binding of [alpha-32P]GTP could be completely prevented by 30 microM GDP or 10 microM guanosine 5'[gamma-thio]triphosphate. This report presents evidence for the presence in a microsomal fraction from zucchini hypocotyls of Gn-proteins as defined by Bhullar and Haslam (1987) Biochem.J. 245, 617-620. The four plant proteins resemble animal Gn-proteins when molecular weights and GTP-binding specificities are considered.

摘要

研究了西葫芦（南瓜属西葫芦种）下胚轴微粒体部分中特定鸟嘌呤核苷酸结合蛋白的存在情况。通过十二烷基硫酸钠聚丙烯酰胺凝胶电泳分离多肽，并将其转移到硝酸纤维素膜上。用[α-32P]GTP和[γ-32P]GTP孵育硝酸纤维素膜印迹表明存在四种特定且不同的GTP结合蛋白，其分子量约为23.4 kDa、24.8 kDa、26.6 kDa和28.5 kDa。30 microM GDP或10 microM鸟苷5'-[γ-硫代]三磷酸可完全阻止[α-32P]GTP的结合。本报告提供了证据，证明西葫芦下胚轴微粒体部分中存在由Bhullar和Haslam（1987年，《生物化学杂志》245卷，617 - 620页）定义的Gn蛋白。当考虑分子量和GTP结合特异性时，这四种植物蛋白类似于动物Gn蛋白。