... of residues 33 , 34 , 35 , 37 , 39 and 40 form a clusterbetween the first (17 33 ) region and second (40–48) a helices. Hydrophobic side chains of residues 43, 47, 50, 55, 56, 59, 60 and 63 form a clusterbetween ... estimated from the ratio between the intensities of the bands at 222 and 208 nm,were 81, 85, 83 and 82% for the solution at pH 6.0, 0%TFE; pH 6.0, 30 % TFE; pH 3. 4, 0% TFE; and pH 3. 4, 30 % TFE, respectively. ... allowing the formation of the hydrophobiccluster that bring close to each other the first and second helices on oneside, and the second and the third helices on the other side.2.6H Tyr50 cH Thr55 3. 5H...