嗜铬粒蛋白中的神经铜蛋白与极酸性铜蛋白的物理化学和抗原特性的相似性。

Similarities of physico-chimical and antigenic properties of neurocupreins and extremely acidic copper proteins from chromaffin granules.

作者信息

Mikaelyan M V, Grigoryan N A, Nalbandyan R M

出版信息

Biochim Biophys Acta. 1987 Jun 22;924(3):548-55. doi: 10.1016/0304-4165(87)90171-1.

Abstract

Extremely acidic copper-containing proteins, neurocupreins, were isolated from brains of various mammals (bovine, rabbit, pig and sheep). Neurocupreins from all these sources were found to have similar physico-chemical and antigenic properties. Using the immunological approach, it was shown that neurocuprein is located only in brain cytosol and synaptosomal fractions. Extremely acidic copper-containing proteins were also isolated from soluble and membranous fractions of chromaffin granules from bovine adrenal medulla. The soluble form of the protein from the granules has practically the same physico-chemical and antigenic properties as neurocupreins. The copper protein isolated from membranes of granules has slightly higher molecular weight and somewhat different amino acid composition, although their EPR spectra are identical. However, both copper proteins from chromaffin granules are immunoprecipitated with antibodies to neurocuprein. It is suggested that the membranous form differs from the soluble one in possessing a peptide which prolongs the protein chain without changes in its antigenic properties.

摘要

从多种哺乳动物（牛、兔、猪和羊）的大脑中分离出了极酸性含铜蛋白——神经铜蛋白。发现来自所有这些来源的神经铜蛋白具有相似的物理化学和抗原特性。采用免疫学方法表明，神经铜蛋白仅位于脑细胞质溶胶和突触体组分中。还从牛肾上腺髓质嗜铬颗粒的可溶性和膜性组分中分离出了极酸性含铜蛋白。颗粒中该蛋白的可溶性形式具有与神经铜蛋白几乎相同的物理化学和抗原特性。从颗粒膜中分离出的铜蛋白分子量略高，氨基酸组成略有不同，尽管它们的电子顺磁共振光谱相同。然而，来自嗜铬颗粒的两种铜蛋白都能用抗神经铜蛋白抗体进行免疫沉淀。有人提出，膜性形式与可溶性形式的不同之处在于它拥有一个能延长蛋白链而不改变其抗原特性的肽段。