A 32‐kDa protein associated with phospholipase A2‐inhibitory activity from human placenta

Abstract
Two monomeric 32‐kDa proteins, termed 32K‐I (pI 5.8) and 32K‐II (pI 5.1), were isolated from human placenta, which was solubilized by a Ca2+‐chelator. Only 32K‐I was associated with PLA2‐inhibitory activity. CNBr peptide mapping indicated that 32K‐I was distinct from 32K‐II and two 36‐kDa proteins, called calpactin I and II or lipocortin II and I, which have been shown to possess PLA2‐inhibitory activity. 32K‐I bound to PS in a Ca2+‐dependent manner. 32K‐I was detected in many tissues except brain, cardiac and skeletal muscle.
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