title: High and low molecular weight proteolytic activities in prawn (Metapenaeus brevicornis) muscle.
abstract: Muscle extract of prawn (Metapenaeus brevicornis) expressed high azocoll lytic activity compared to extracts of many other prawn varieties; the activity was also inhibited to a small extent by dithiothreitol. Ammonium sulphate precipitation, subsequent extraction at pH 5.6 and chromatography revealed the occurrence of two types of azocoll lytic activities: one, high molecular weight (630 kDa) and the other low molecular weight (< 30 kDa) enzyme. The former was stimulated by dithiothreitol whereas the latter was inhibited. SDS PAGE of high molecular weight preparation did not show homogeneity but the profile was similar to that of the low molecular weight fraction. Gel filtration of high molecular weight enzyme following incubation at high pH revealed the formation of low molecular weight fractions having activity towards azocoll. Chymotrypsin-like activity associated with high molecular weight enzyme was also susceptible to dissociation by high pH. Azocoll lytic activity of both enzymes was strongly inhibited by 1,10-phenanthroline.
authors.affiliation: Food Technology Division, Bhabha Atomic Research Centre, Trombay, Mumbai.
authors.forename: M N
authors.initials: MN
authors.lastname: Karani
authors.forename: M S
authors.initials: MS
authors.lastname: Gore
authors.forename: P M
authors.initials: PM
authors.lastname: Nair
mesh_terms: D000818:Animals; D002853:Chromatography, Liquid; D004591:Electrophoresis, Polyacrylamide Gel; D010450:Endopeptidases / Q000302:isolation & purification* / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D008970:Molecular Weight; D009132:Muscles / Q000201:enzymology*; D033561:Penaeidae; D012967:Sodium Dodecyl Sulfate / Q000737:chemistry; D013696:Temperature
chemical_list: D012967:Sodium Dodecyl Sulfate; D010450:Endopeptidases