It has been reported that Cys283 in the rabbit muscle creatine kinase is the active site, and this residue is a highly conservative site among creatine kinases and arginine kinases, Cys274 in sea cucumber arginine kinase for example.

• 曾经有报道证明兔肌肌酸激酶的Cys283是活性位点,而这个Cys残基正好是各种肌酸激酶和精氨酸激酶在进化中高度保守的位点,在海参精氨酸激酶中即是Cys274。