Interaction of calcium with porcine adrenal chromogranin A (secretory protein-I) and chromogranin B (secretogranin I)

S. U. Gorr, J. Shioi, D. V. Cohn

Research output: Contribution to journalArticle

76 Scopus citations

Abstract

Secretory granules of endocrine cells contain one or more of the acidic secretory proteins chromogranin A (secretory protein-I), chromogranin B (secretogranin I), and secretogranin II (chromogranin C). It has been proposed that these proteins play a role in the packaging of secretory products. In the present study, lysates of purified porcine adrenal chromaffin granules containing chromogranins A and B and a putative chromogranin B fragment bound calcium and formed aggregates in the presence of 10-20 mM calcium at pH 5-6 and at 100 mM or less KCl, NaCl, or norepinephrine. The precipitates contained virtually all of the chromogranin B and the chromogranin B fragment and about one-third of the chromogranin A. The aggregates did not form or were dissociated at the pH and salt concentration of the extracellular fluid. Calcium precipitated purified chromogranin A and chromogranin B from pure solution to the same extent as from the granule lysates. Parathormone, added to the lysates, was incorporated in the precipitates, whereas the acidic secretory protein ovalbumin and norepinephrine were not. These findings suggest that secretory protein-I and secretogranin can exist in situ as aggregates that may include selected secretory products.

Original languageEnglish (US)
Pages (from-to)20/2
JournalAmerican Journal of Physiology - Endocrinology and Metabolism
Volume257
Issue number2
StatePublished - 1989

Fingerprint Dive into the research topics of 'Interaction of calcium with porcine adrenal chromogranin A (secretory protein-I) and chromogranin B (secretogranin I)'. Together they form a unique fingerprint.

Cite this