Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: UMLS:C1389183 (
autodigestion
)
317
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Mn2+
(50 microM) satisfies the requirement for activity of the purified Ca2+-dependent neutral proteinase from human erythrocytes. Unlike the activation by Ca2+ [E. Melloni et al. (1984) Biochem. Int. 8, 477-489], the effect of
Mn2+
is fully reversible and does not involve
autodigestion
of the native 80-kDa catalytic subunit. However, the native dimeric proenzyme (procalpain), which contains both the 80-kDa subunit and a smaller 30-kDa subunit, is not activated by
Mn2+
alone but also requires the presence of micromolar concentrations of Ca2+. Under these conditions, 40% of the maximum activity is expressed without dissociation of the 80- and 30-kDa subunits.
Mn2+
, but not micromolar Ca2+, can also partially satisfy the metal requirement of the native 80-kDa subunit isolated after dissociation of the heterodimer. This activity is further enhanced by the addition of 5 microM Ca2+, which is ineffective in the absence of
Mn2+
. After procalpain is converted to active calpain by incubation with Ca2+ and substrate [S. Pontremoli et al. (1984) Biochem. Biophys. Res. Commun. 123, 331-337] full activity is observed with 5 microM
Mn2+
, which now substitutes completely for Ca2+. Activation of procalpain by
Mn2+
represents a new mechanism for modulation of the Ca2+-dependent proteinase activity.
...
PMID:The reversible activation by Mn2+ ions of the Ca2+-requiring neutral proteinase of human erythrocytes. 298 54
