“…Calculation of the hydrophobicity profile of the a-subunit allowed the prediction of eleven probable transmembrane clusters [1,3]: 89-l 14, 123-142., 284-306, 313-341, 530-554, 569-597, 780-803, 842-867, 909-930, 946-971, 973-994. Previously, we established conditions for trypsinolysis of the membrane-bound enzyme (0.1 N NH4HCO3, pH 7.3; 1% trypsin, 10 min), providing exhaustive hydrolysis of the exposed regions of the polypeptide chain of the catalytic subunit [3,12].…”