The Enzyme

The enzymes of the phospholipase A2 superfamily can be divided into two general categories. The first category, the Histidine enzymes, contains the small (< 20,000 kD) enzymes that are secreted, have a large number of disulfide bonds, require Ca2+ for catalysis, and possess an His/Asp pair in the catalytic site. This category currently contains seven groups of distinct enzymes.

The second category, the Serine enzymes, contains four groups of enzymes, that do not require Ca2+, are larger than 20,000 kD, and have a catalytic Ser.