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PROTEIN DEGRADATION IN SQUID GIANT AXONS
Author(s) -
Orrego F.
Publication year - 1971
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1971.tb00181.x
Subject(s) - axoplasm , squid , biochemistry , chemistry , biophysics , squid giant axon , divalent , biology , axon , anatomy , membrane potential , ecology , organic chemistry
— Axoplasm extruded from giant axons of the Chilean squid, Dosidicus gigas , contained a low level of neutral proteinase‐like activity, equivalent to 4 × 10 −6 mg of chymotrypsin per mg of axoplasmic protein. The enzyme was active at physiological pH and ionic strength. Activity was completely inhibited by 1 mM‐para‐hydroxymercuribenzoate and was enhanced by divalent metal cations, especially Ca 2+ . Axoplasm also exhibited proteinase activity at pH 4.8. Both neutral and acid proteinase like activities were also present in the axonal sheath containing Schwann cells, but their specific activities relative to those in the axoplasm were different. A physiological role, related to the axoplasmic flow of protein, is discussed for the axoplasmic neutral proteinase‐like activity.