Our recent investigations have established that the formation of helical supramolecular complexes of amyloae 1 or its derivatives with long-chain substrates in both aqueous and DMSO=H₂O mixed-solvent systems is accompanied by conformational changes of the macromolecules.This paper reports the resalta from an investigation of the hydrolysis of five esters of p-nitrophenol, to wit, the acetate 2,the valerate 3; the caprylate 4, the laurate 6 and the palmitate 6, in the 1:1.V/V DMSO-H₂O mixture with amyloae 1 as a catalyat.Two buffers were used, viz.0.01 M sodium borate or sodium bicarbonate; their pH values are 9.5 in pure water.The observed rate constants, k_obs, for the hydrolysis of the substrates were determined by monitoring the absorbance at 410 nm.