Serine endopeptidase which is involved in the processing of hormone and other protein precursors at sites comprised of pairs of basic amino acid residues (PubMed:28719828, PubMed:7626024, PubMed:8879041, PubMed:9287128). Responsible for the release of glucagon from proglucagon in pancreatic A cells (PubMed:9287128). Mediates the release of insulin from proinsulin (PubMed:7626024). {ECO:0000269|PubMed:28719828, ECO:0000269|PubMed:7626024, ECO:0000269|PubMed:8879041, ECO:0000269|PubMed:9287128}. This is the function of PCSK2 (proprotein convertase subtilisin/kexin type 2, ENSG00000125851).