C4b-binding protein alpha chain (C4bp) (Proline-rich protein) (PRP)
1_MHPPK 6_ TPSGA 11_ LHRKR 16_ KMAAW 21_ PFSRL 26_ WKVSD 31_ PILFQ 36_ MTLIA 41_ ALLPA 46_ VLGNC 51_ GPPPT 56_ LSFAA 61_ PMDIT 66_ LTETR 71_ FKTGT 76_ TLKYT 81_ CLPGY 86_ VRSHS 91_ TQTLT 96_ CNSDG 101_ EWVYN 106_ TFCIY 111_ KRCRH 116_ PGELR 121_ NGQVE 126_ IKTDL 131_ SFGSQ 136_ IEFSC 141_ SEGFF 146_ LIGST 151_ TSRCE 156_ VQDRG 161_ VGWSH 166_ PLPQC 171_ EIVKC 176_ KPPPD 181_ IRNGR 186_ HSGEE 191_ NFYAY 196_ GFSVT 201_ YSCDP 206_ RFSLL 211_ GHASI 216_ SCTVE 221_ NETIG 226_ VWRPS 231_ PPTCE 236_ KITCR 241_ KPDVS 246_ HGEMV 251_ SGFGP 256_ IYNYK 261_ DTIVF 266_ KCQKG 271_ FVLRG 276_ SSVIH 281_ CDADS 286_ KWNPS 291_ PPACE 296_ PNSCI 301_ NLPDI 306_ PHASW 311_ ETYPR 316_ PTKED 321_ VYVVG 326_ TVLRY 331_ RCHPG 336_ YKPTT 341_ DEPTT 346_ VICQK 351_ NLRWT 356_ PYQGC 361_ EALCC 366_ PEPKL 371_ NNGEI 376_ TQHRK 381_ SRPAN 386_ HCVYF 391_ YGDEI 396_ SFSCH 401_ ETSRF 406_ SAICQ 411_ GDGTW 416_ SPRTP 421_ SCGDI 426_ CNFPP 431_ KIAHG 436_ HYKQS 441_ SSYSF 446_ FKEEI 451_ IYECD 456_ KGYIL 461_ VGQAK 466_ LSCSY 471_ SHWSA 476_ PAPQC 481_ KALCR 486_ KPELV 491_ NGRLS 496_ VDKDQ 501_ YVEPE 506_ NVTIQ 511_ CDSGY 516_ GVVGP 521_ QSITC 526_ SGNRT 531_ WYPEV 536_ PKCEW 541_ ETPEG 546_ CEQVL 551_ TGKRL 556_ MQCLP 561_ NPEDV 566_ KMALE 571_ VYKLS 576_ LEIEQ 581_ LELQR 586_ DSARQ 591_STLDK
1: Controls the classical pathway of complement activation. It binds as a cofactor to C3b/C4b inactivator (C3bINA), which then hydrolyzes the complement fragment C4b. It also accelerates the degradation of the C4bC2a complex (C3 convertase) by dissociating the complement fragment C2a. Alpha chain binds C4b. It also interacts with anticoagulant protein S and with serum amyloid P component