Modulation of Mucor miehei lipase properties via directed immobilization on different hetero-functional epoxy resins -: Hydrolytic resolution of (R,S)-2-butyroyl-2-phenylacetic acid

Purified lipase from Mucor miehei (MML) has been covalently immobilized on different epoxy resins (standard hydrophobic epoxy resins, epoxy-ethylenediamine, epoxy-immodiacetic acid, epoxy-copper chelates) and adsorbed via interfacial activation on octadecyl-Sepabeads support (fully coated with very hydrophobic octadecyl groups). These immobilized enzyme preparations were used under slightly different conditions (temperature ranging from 4 to 25 degreesC and pH values from 5 to 7) in the hydrolytic resolution of (R,S)-2-butyroyl-2-phenylacetic acid. Different catalytic properties (activity, specificity, enantioselectivity) were found depending on the particular support used. For example, the epoxy-iminodiacetic acid-Sepabeads gave the most active preparation at pH 7 while, at pH 5, the ethylenediamine-Sepabeads was superior. More interestingly, the enantiomeric ratio (E) also depends strongly on the immobilized preparation and the conditions employed. Thus, the octadecyl-MML preparation was the only immobilized enzyme derivative which exhibited enantioselectivity towards R isomer (with E values ranging from 5 at 4 degreesC and pH 7 to 1.2 at pH 5 and 25 degreesC). The other immobilized preparations, in contrast, were S selective. Immobilization on iminodiacetic acid-Sepabeads afforded the catalyst with the highest enantioselectivity (E = 59 under optimum conditions). (C) 2002 Elsevier Science B.V. All rights reserved.