The amino terminal sequences of bovine and human chromogranin A and secretory protein I are identical.

The amino terminal sequences of bovine and human adrenal medullary chromogranin A have been determined. Their sequences are identical and also identical to the published sequence of secretory protein I from the parathyroid gland. This data indicates that the previously published sequence of chromogranin A is incorrect at residues 2 and 19. These data confirm earlier observations of a substantial similarity between secretory protein I and chromogranin A and, in fact, strongly suggest that they are identical.