Isolation and N-terminal sequence of two low molecular weight calcium-binding proteins from pig granulocytes

1. Two small, abundant calcium-binding proteins were isolated from pig granulocytes. They were named p7A and p7B. Relative molecular masses were approx. 32,000 for p7A and 13,000 for p7B, when obtained by Sephadex G-75 gel filtration, while it was 7000 for both proteins by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). 2. N-terminal sequence analysis suggests that p7A is homologous to human and mouse MRP-8 and that p7B may be related to human and mouse MRP-14, though some properties of the latter--such as mobility on SDS-PAGE--were found to be different. In addition, p7A and p7B could be resolved under native conditions, contrasting with the fact that human and mouse MRP-8/MRP-14 form noncovalent complexes.