Calcium-activated, phospholipid-dependent protein kinase in pig epidermis

We investigated calcium-activated, phospholipid-dependent protein kinase in pig epidermis. Pig epidermal homogenates were centrifuged at 30,000 g for 30 min, and the supernatant was applied on a DEAE-cellulose column for purification. The partially purified enzyme was stimulated by simultaneous addition of Ca2+ and phospholipid. Successive addition of small amounts of diolein further activated the enzyme activity. The calcium-activated phospholipid-dependent protein kinase preferentially phosphorylated serine residues and its endogenous substrate protein in the pig epidermis has a molecular weight of about 97,000.