PMID-sentid Pub_year Sent_text comp_official_name comp_offsetprotein_name organism prot_offset 1911746-7 1991 Ca(2+)-dependent chromaffin granule membrane aggregation, induced by p32 or synexin, was associated with intermembrane annexin polymerization at Ca2+ levels less than pCa 4, but not at higher Ca2+ concentrations, suggesting that annexin self-association may be necessary for membrane contact at low Ca2+ levels but not at higher Ca2+ levels where the protein may bind two membranes as a monomer. chromaffin 17-27 annexin A7 Homo sapiens 76-83