151. Rapid, high-yield isolation of human chromogranin A from chromaffin granules of pheochromocytomas.
- Author
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Syversen U, Waldum HL, and O'Connor DT
- Subjects
- Adrenal Gland Neoplasms ultrastructure, Amino Acid Sequence, Chromatography, Affinity, Chromatography, Gel, Chromogranin A, Chromogranins chemistry, Electrophoresis, Polyacrylamide Gel, Humans, Immunoblotting, Microscopy, Electron, Molecular Sequence Data, Pheochromocytoma ultrastructure, Adrenal Gland Neoplasms chemistry, Chromaffin Granules chemistry, Chromogranins isolation & purification, Pheochromocytoma chemistry
- Abstract
Chromogranin A (CgA) is a useful probe of human neuroendocrine neoplasia and exocytotic sympathoadrenal activity, but the application of CgA immunoassays has not been widespread because of limited availability of purified human CgA. Here we describe a rapid, high yield isolation of human CgA. After obtaining and lysing pheochromocytoma chromaffin granules, the soluble core proteins (chromogranins) were depleted of dopamine-beta-hydroxylase by passage over a concanavalin A-Sepharose affinity column, then lyophilized, resuspended in volatile buffer, and gel filtered on Sephacryl S-300. SDS-PAGE-analyzed column fractions contained homogeneous human CgA, which was verified structurally (N-terminal amino acid sequence) and immunologically (radioimmunoassay and immunoblot). The overall 22.6 mg yield of purified CgA represented 5.7% of the starting vesicle core protein. This preparation will be useful in evaluating the sympathoadrenal system and endocrine neoplasia in man.
- Published
- 1992
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