Characterisation of a plasma membrane-associated phospholipase A(2) activity increased in response to cold acclimation
We here demonstrate the presence of a plasma membrane-associated phospholipase A(2) (EC 3.1.1.4; PLA(2)) activity in spinach (Spinacia oleracea) leaves. The pH profile of the spinach plasma membrane PLA(2) activity revealed two peaks, one at pH 4.4 and one at pH 5.5. The activity at pH 5.5 had an absolute requirement of Ca2+, with full enzyme activity at 10mumol/L Ca2+. The Ca2+-dependent PLA(2) a
