to control for positional effects , all four permutations of lysine and arginine ( lys-arg , arg-arg , arg-lys , and lys-lys ) were introduced at both the efficiently processed cleavage site separating the acth and beta-lipotropin ( beta-lph ) domains of pomc and at the inefficiently processed site in the beta-endorphin sequence near the cooh-terminus of the precursor .
C0023832
beta-lipotropin
C0033195
pomc