Microheterogeneity of human plasma lecithin: cholesterol acyltransferase examined by isoelectric focusing in immobilized pH gradients.

The microheterogeneity of highly purified human plasma lecithin:cholesterol acyltransferase (LCAT) has been examined by electrophoresis in immobilized pH gradients in Immobiline-polyacrylamide gels of the pH ranges 4-7 and 4.2-4.9. Seven isoforms were obtained with LCAT isolated from pools of normal plasma. Using this technique the apparent pI values at 15 degrees C for the isoforms in the pH 4.2-4.9 gradient were 4.37, 4.42, 4.48, 4.53, 4.60, 4.67 and 4.74. (SD = +/- 0.03 for all). The most intensely stained band in the isoform pattern corresponded to the isoform with a pI value of 4.48.