Settleman J, Fonseca R, Nolan J, Angeletti R H
J Biol Chem. 1985 Feb 10;260(3):1645-51.
Chromogranin polypeptides of Mr 100,000, Mr 85,000, Mr 75,000, and Mr 65,000 have been detected in adrenal medulla chromaffin granules using anti-chromogranin antiserum. Monoclonal antibodies to this protein also detect the multiple molecular weight chromogranin polypeptides. Analysis of phosphorylated amino acids gives a value of 5 phosphoserine residues/mol of Mr 75,000 chromogranin polypeptide. Immunological analysis of dephosphorylated chromogranin shows that the anti-chromogranin serum reacts with both the phosphorylated and unphosphorylated forms of the protein. Each of the chromogranin polypeptides has been isolated using a combination of DEAE-cellulose chromatography and reverse phase high pressure liquid chromatography. Sequencer analysis of each protein revealed a high degree of amino acid identities at the amino terminal of these proteins. Amino-terminal Sequencer analysis of chromogranin fragments also provides evidence for a gene duplication event. Preliminary studies also show that chromogranin may be degraded in the chromaffin granules by a calcium-dependent mechanism.
使用抗嗜铬粒蛋白抗血清在肾上腺髓质嗜铬颗粒中检测到了分子量为100,000、85,000、75,000和65,000的嗜铬粒蛋白多肽。针对该蛋白的单克隆抗体也能检测到多种分子量的嗜铬粒蛋白多肽。对磷酸化氨基酸的分析得出，每摩尔分子量为75,000的嗜铬粒蛋白多肽含有5个磷酸丝氨酸残基。对去磷酸化嗜铬粒蛋白的免疫分析表明，抗嗜铬粒蛋白血清能与该蛋白的磷酸化形式和未磷酸化形式发生反应。每种嗜铬粒蛋白多肽都通过二乙氨基乙基纤维素色谱法和反相高压液相色谱法相结合的方法进行了分离。对每种蛋白质的序列分析显示，这些蛋白质在氨基末端具有高度的氨基酸同源性。对嗜铬粒蛋白片段的氨基末端序列分析也为基因复制事件提供了证据。初步研究还表明，嗜铬粒蛋白可能在嗜铬颗粒中通过一种钙依赖性机制被降解。
