Are part of a large chaperone multiprotein complex and inhibit aggregation of misfolded proteins that play a role in the folding of disulfide-bonded proteins; P4hb, prolyl 4-hydroxylase beta polypeptide, also a member of the protein disulfide isomerase family and at low concentrations facilitates protein aggregation (anti-chaperone) whereas at high concentrations inhibits protein aggregation (chap