TY - JOUR
T1 - The high molecular weight multicatalytic proteinase, macropain, exists in a latent form in human erythrocytes
AU - McGuire, Michael J.
AU - McCullough, Marci L.
AU - Croall, Dorothy E.
AU - DeMartino, George N.
N1 - Funding Information:
This work was supportedb y grantsf rom the Na-tionalI nstituteos f Health( DK 29829a nd DK 07593). We thank GeorgiaG reenand ElizabethW isakowsky for typingt hemanuscript.
PY - 1989/4/6
Y1 - 1989/4/6
N2 - The high molecular weight multicatalytic proteinase, macropain, has been purified from human erythrocytes in two forms that differ in caseinolytic activity up to 100-fold. Each form has a native molecular weight of 600 000 and is composed of a number of subunits ranging in molecular weights from 35 000 to 21 000. Although the two proteinase forms share a number of electrophoretically indistinguishable subunits, there are also subunits unique to the respective forms. The less active proteinase represents a latent enzyme because it was fully activated by two procedures including dialysis against water and pretreatment with low concentrations of sodium dodecyl sulfate. These procedures caused differential changes in the caseinolytic and two peptidase activities of the proteinase. An Mr 35 000 subunit, characteristic of latent macropain, is immunologically related to at least one of the other components of active macropain and disappeared after proteinase activation by dialysis. Nevertheless, loss of this subunit was not the cause of the increased activity. These results suggest that the proteolytic activity of cells may be regulated by the activation of the latent form of macropain.
AB - The high molecular weight multicatalytic proteinase, macropain, has been purified from human erythrocytes in two forms that differ in caseinolytic activity up to 100-fold. Each form has a native molecular weight of 600 000 and is composed of a number of subunits ranging in molecular weights from 35 000 to 21 000. Although the two proteinase forms share a number of electrophoretically indistinguishable subunits, there are also subunits unique to the respective forms. The less active proteinase represents a latent enzyme because it was fully activated by two procedures including dialysis against water and pretreatment with low concentrations of sodium dodecyl sulfate. These procedures caused differential changes in the caseinolytic and two peptidase activities of the proteinase. An Mr 35 000 subunit, characteristic of latent macropain, is immunologically related to at least one of the other components of active macropain and disappeared after proteinase activation by dialysis. Nevertheless, loss of this subunit was not the cause of the increased activity. These results suggest that the proteolytic activity of cells may be regulated by the activation of the latent form of macropain.
KW - (Human erythrocyte)
KW - Laten form
KW - Macropain
KW - Multicatalytic proteinase
KW - Proteinase
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U2 - 10.1016/0167-4838(89)90078-2
DO - 10.1016/0167-4838(89)90078-2
M3 - Article
C2 - 2930796
AN - SCOPUS:0024600924
SN - 0167-4838
VL - 995
SP - 181
EP - 186
JO - Biochimica et Biophysica Acta (BBA)/Protein Structure and Molecular
JF - Biochimica et Biophysica Acta (BBA)/Protein Structure and Molecular
IS - 2
ER -