Reports

Protein Digestion in Isolated Lysosomes Inhibited by Intralysosomal Trypan Blue

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Science  28 Mar 1969:
Vol. 163, Issue 3874, pp. 1454-1456
DOI: 10.1126/science.163.3874.1454

Abstract

Control rats and rats treated with subcutaneous trypan blue were injected intravenously with denatured albumin-I125. Lysosome-rich fractions of their livers, when incubated at 22°C in osmotically protected medium (pH 7.4), retained their capacit to digest albumin-I125. The rate of digestion was lower in suspensions pre-pared from rats treated with trypan blue than in control suspensions, but rates of lysosome breakage were not different. T'hese results and other experimental evidence suggest that trypanblue concentrated within lysosomes can inhibit intralysosomal digestion, probably by inhibition of lysosomal proteinases.