CALCA GI:4502545 calcitonin isoform CALCA preproprotein 1 mgfqkfspfl alsilvllqa gslhaapfrs alesspadpa tlsedearll 50 51 laalvqdyvq mkaseleqeq eregssldsp rskrcgnlst cmlgtytqdf 100 101 nkfhtfpqta igvgapgkkr dmssdlerdh rphvsmpqna n