Transcobalamins are carrier proteins which bind cyanocobalamin (B12).
serpins: alpha-1 (Alpha 1-antichymotrypsin, Alpha 1-antitrypsin) · alpha-2 (Alpha 2-antiplasmin) · Antithrombin (Heparin cofactor II)
carrier proteins: alpha-1 (Transcortin) · alpha-2 (Ceruloplasmin) · Retinol binding protein
carrier proteins: Sex hormone-binding globulin · Transferrin