羧基末端修饰对人β-血红蛋白寡聚结构的影响。

Effect of carboxyterminal modification on the oligomeric structure of human beta hemoglobin.

作者信息

Moulton D P, Joshi A A, Morris A, McDonald M J

机构信息

Department of Chemistry, College of Arts and Sciences, University of Massachusetts, Lowell 01854.

出版信息

Biochem Biophys Res Commun. 1994 Oct 28;204(2):956-61. doi: 10.1006/bbrc.1994.2553.

DOI:10.1006/bbrc.1994.2553

PMID:7980567

Abstract

A broad beta chain band region containing multiple components was observed with both native beta and Des(His-146, Tyr-145) beta chains following isoelectric focusing on agarose gels (pH 6.0-8.0). In contrast to the tetramer-monomer system of beta chains, a distinct separation of three components (tetramer, dimer and monomer) was seen for Des(His-146, Tyr-145) beta chains indicative of an oligomeric structural beta model with a stable dimer species. Protein dilution (500 to 15.6 microM in heme) amplified the more cathodic (presumably dimeric and monomeric) components of these chains, and titration with partner alpha chains resulted in a selective depletion of the monomer (most cathodic) component which could be quantitatively correlated with assembly of the hemoglobin tetramer.

摘要

在琼脂糖凝胶（pH 6.0 - 8.0）上进行等电聚焦后，天然β链和去（组氨酸 - 146，酪氨酸 - 145）β链均观察到一个包含多个成分的宽β链带区。与β链的四聚体 - 单体体系不同，去（组氨酸 - 146，酪氨酸 - 145）β链可明显分离出三种成分（四聚体、二聚体和单体），这表明存在一种具有稳定二聚体形式的寡聚结构β模型。蛋白质稀释（在血红素中从500 microM至15.6 microM）增强了这些链中更多向阴极迁移的（可能是二聚体和单体）成分，并且与伙伴α链进行滴定导致单体（最向阴极迁移）成分的选择性消耗，这可以与血红蛋白四聚体的组装进行定量关联。