Über den Enzymatischen Cutin-Abbau. II. Mitteilung: Eigenschaften eines Cutinolytischen Enzyms aus Penicillium spinulosum Thom

1) A cutinolytic enzyme present in extracts of P. spinulosum was enriched by purification of the extract with protamine sulfate followed by treatment with ammonium sulfate at 70 % salt concentration. A separation from disturbing enzymes is obtained this way. 2) Determination of the optimum reaction conditions gave these results: Optimum of substrate concentration 1,0-1,5 mg cutin/ml enzyme solution, independence of the reaction from temperature between 15-35° C, pH-optimum at pH 6,0 and proportionallity between concentration of enzyme and destruction of substrate from 7,5 to 22,5 mg dry weight per ml sample. 3) Examination of substrate specifity with different cutins from leaves, fruits and stamps showed, that cutin isolated of stamps is much better attacked than all other materials tested. 4) The stability of the enzyme against H-ion concentration, temperature, aging and dialysis has been tested. According to the results obtained, cutinase is a stable enzyme needing no dialysable co-factors. Evidence has been made, that cutinase is inactivated by shaking. 5) Further examinations were done for genera! characterisation of the enzyme but failed in getting a definition about the enzymes’ mechanism of action. Cutinase is not localized in the mitochondrial fraction but in the cytoplasm of the cell.