Cloning and recombinant expression of human group IIF-secreted phospholipase A(2)

Mammalian-secreted phospholipases A(2) (sPLA(2)) form a diverse family of a t least nine enzymes that hydrolyze phospholipids to release free fatty aci ds and lysophospholipids. We report here the cloning and characterization o f human group IIF sPLA(2) (hGIIF sPLA(2)). The full-length cDNA codes for a signal peptide of 20 amino acid followed by a mature protein of 148 amino acids containing all of the structural features of catalytically active gro up II sPLA(2)s. hGIIF sPLA(2) gene is located on chromosome 1 and lies with in a sPLA(2) gene cluster of about 300 kbp that also contains the genes for group LIA, IIC, IID, IIE, and V sPLA(2)s. In adult tissues, hGIIF is highl y expressed in placenta, testis, thymus, liver, and kidney. Finally, recomb inant expression of hGIIF sPLA(2) in Escherichia coli shows that the enzyme is Ca2+-dependent, maximally active at pH 7-8, and hydrolyzes phosphatidyl glycerol versus phosphatidylcholine with a 15-fold preference. (C) 2000 Aca demic Press.