a lysate of purified insulin secretory granules , which contains two types of proinsulin processing activity ( type 1 , arg-arg-directed and type ii , lys-arg-directed ( davidson , h.w. , rhodes , c.j. , and hutton , j. c. ( 1988 ) nature 333 , 93-96 ) , was found to process proalbumin by specific proteolytic cleavage of the cooh-terminal side of the arg-2-arg-1 sequence .
C0021641
insulin
C0033362
proinsulin