Comparative Study on the Characteristics of Midgut Protease in Different Multivoltine Races of Silkworm, Bombyx mori L.
Y. S. Muniv* and G. P. Bhawane**
Journal Title:Biological Forum-An International Journal
ABSTRACT : Proteolytic activity from the midgut of the lepidopteran larvae Bombyx mori was studied in relation to compare the characterization in three different multivoltine races, Pure Mysore, Nistari and Kolar gold. The optimum pH for the midgut protease was 11.2 in Pure Mysore and Nistari, while it was 11.0 in Kolar gold. The temperature optimum for Pure Mysore was 50°C, while it was 45°C for Nistari and Kolar gold. Incubation of the gut protease for 15 minutes was found as a linear time period in Nistari while that of 20 minutes in Pure Mysore and Kolar gold. The 50% reduction in activity at 55°C, for 7.3 minutes was found in Nistari, 9.6 minutes for Pure Mysore and 10.7 minutes for Kolar gold. Km values recorded were 0.278%, 0.167% and 0.222% in Pure Mysore, Nistari and Kolar gold respectively. The specific activity of Pure Mysore was 0.611 ?g tyrosine/?g protein/h; Nistari was 0.916?g tyrosine/?g protein/h, while that of Kolar gold was 0.546?g tyrosine/?g protein/h.