Nonionic tensides modify papain structure and proteolytic activity

Abstract

The effect of 33 polyethoxylated nonionic tensides with various hydrophobic moieties was studied on the proteolytic activity and phase transition behaviour of papain. Tensides with longer ethyleneoxide chain markedly increased the phase transition temperatures of papain indicating possible hydrogen bond formation between the hydrophilic ethyleneoxide chain and the polar substructures of papein. The character of Iipophilic moiety of tensides influences also each physicochemical parameter of papain suggesting the existence of hydrophobic interactions too. The significant positive linear correlations between the activity increasing and structure stabilizing effects of tensides make probably that the structure modification of papain accounts for its enchanced proteolytic activity. IntroductionNonionic tensides are widely used for many purposes, as in pesticide and pharmaceutical formulations. The concomitant toxic phenomena are also varied. Although they are easily biodegredable they nevertheless decrease the performance of activated sludge systems [l, 21, damage pine trees by increasing the uptake of sodium ions [3,4,5], and by dissolving the surface wax layer of pine needles [6]. Tensides exert an inhibitory effect on the growth of Spirodela polyrrhiza (L) Schleiden [7], they are lethal to Medaka

Alkyl Ethoxylated and Alkylphenol Ethoxylated Nonionic Surfactants: Interaction with Bioactive Compounds and Biological Effects

“…Nonhomologous series of nonionic surfac-tants increased the activity of papain and modified its structure as determined by differential scanning calorimetry. Both the hydrophobic and hydrophilic molecular characteristics of surfactants influenced their effect on the activity and structure of papain (55). In contrast, similar surfactants markedly inhibited the activity of horseradish peroxidase.…”