CST2 GI:4503105 cystatin SA precursor 1 mawplctlll llatqavala wspqeedrii eggiydadln dervqralhf 50 51 viseynkate deyyrrllrv lrareqivgg vnyffdievg rtictksqpn 100 101 ldtcafheqp elqkkqlcsf qiyevpwedr mslvnsrcqe a