Purification and characterization of a latent form of multicatalytic proteinase from fish muscle

BUSCONI L., FOLCO E.J.E., STUDDERT C.A. AND SÁNCHEZ J.J.

COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. PART B, BIOCHEMISTRY & MOLECULAR BIOLOGY.

Año: 1992 vol. 102 p. 303 - 309

1096-4959

A latent form of multicatalytic proteinase (MCP) was purified to apparent homogeneity from white croaker muscle by DEAE-Sephacel, Mono-Q, Sephacryl S-300 and second Mono-Q chromatographies. The enzyme preparation was electrophoretically and immunologically similar to MCP purified from the same source by a different method (Folco et al., 1988b, Arch Biochem Biophys 267, 599-605) but showed much lower chymotripsin- and trypsin-like activities. These activities responded to sodium dodecyl sulphate (SDS), urea and heat treatments in different ways: SDS stimulated both activities, urea stimulated the former and inhibited the latter and heating stimulated the former and did not affect the latter. The stimulation of chymotrypsin-like activity by the three treatments was irreversible. Exposure of MCP to SDS or urea in the absence of substrate rapidly inactivated it, whereas heat activation took place irrespective of the presence of substrate. The stimulating effect of SDS on chymotripsin-like was lost in the presence of urea. These results suggest that the enzyme may be activated by different mechanisms. Se adjunta como pdf la primera página scanneada