Abstract: Systematic infection of tomato (Lycopersicon esculenturn) leaves by tobacco mosaic virus (TMV) increased the levels of β-N-acetyl-D-hexosaminidase activity. The enzyme was purified from intercellular fluid by --20℃ acetone precipitation, CM-Sephadex C-25 ion exchange chromatography, Polybuffer Exchanger 94 chromatofocusing and Sephadex G-150 gel filtration column to homogeneity. The molecular weight obtained by SDS-PAGE and Sephadex G-150 gel filtration was 75 kD and 145 kD respectively. The enzyme hydrolysed p-nitrophenyl-N-acetyl-β-glucosaminide and p-nitrophenyl-N-acetyl-β-galaetosaminide, it was a glycoprotein. Most of the enzyme activity in the TMV-infected tomato leaves was found in the intercellular spaces.

Key words: Tomato, Tobacco mosaic virus, β-N-acetyl-D-hexosaminidase