Abstract
Class II MHC-associated invariant chain (Ii) might regulate binding of digested peptides to the Ag binding site (desetope) of class II MHC proteins by directly or allosterically blocking that site until cleavage and release of Ii from MHC α- and β-chains at the time of peptide charging. We examined the cleavage and release of Ii from class II MHC α/β/Ii trimers by cathepsin B, which has been shown by others to colocalize with class II MHC molecules in intracellular compartments and to generate antigenic peptide fragments. Cathepsin B at pH 5.0 cleaved and released Ii from class II MHC α- and β-chains. Cathepsin B digested Ii from α- and β-chains in a dose-dependent fashion, yielding 23-, 21-, and 10-kDa fragments. Blockage of cathepsin B activity with leupeptin restored the 2D(nonequilibrium pH gradient gel electrophoresis/SDS) PAGE patterns of Ii and sialic acid-derivatized forms of Ii seen without the protease. The fragmentation pattern of cathepsin D treatment was different from that of cathepsin B, yielding 25-kDa intermediates.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 3877-3880 |
| Number of pages | 4 |
| Journal | Journal of Immunology |
| Volume | 146 |
| Issue number | 11 |
| State | Published - Jun 1 1991 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Immunology
Cite this
Cathepsin B cleavage of Ii from class II MHC α- and β-chains. / Reyes, Victor; Lu, Shan; Humphreys, Robert E.
In: Journal of Immunology, Vol. 146, No. 11, 01.06.1991, p. 3877-3880.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Cathepsin B cleavage of Ii from class II MHC α- and β-chains
AU - Reyes, Victor
AU - Lu, Shan
AU - Humphreys, Robert E.
PY - 1991/6/1
Y1 - 1991/6/1
N2 - Class II MHC-associated invariant chain (Ii) might regulate binding of digested peptides to the Ag binding site (desetope) of class II MHC proteins by directly or allosterically blocking that site until cleavage and release of Ii from MHC α- and β-chains at the time of peptide charging. We examined the cleavage and release of Ii from class II MHC α/β/Ii trimers by cathepsin B, which has been shown by others to colocalize with class II MHC molecules in intracellular compartments and to generate antigenic peptide fragments. Cathepsin B at pH 5.0 cleaved and released Ii from class II MHC α- and β-chains. Cathepsin B digested Ii from α- and β-chains in a dose-dependent fashion, yielding 23-, 21-, and 10-kDa fragments. Blockage of cathepsin B activity with leupeptin restored the 2D(nonequilibrium pH gradient gel electrophoresis/SDS) PAGE patterns of Ii and sialic acid-derivatized forms of Ii seen without the protease. The fragmentation pattern of cathepsin D treatment was different from that of cathepsin B, yielding 25-kDa intermediates.
AB - Class II MHC-associated invariant chain (Ii) might regulate binding of digested peptides to the Ag binding site (desetope) of class II MHC proteins by directly or allosterically blocking that site until cleavage and release of Ii from MHC α- and β-chains at the time of peptide charging. We examined the cleavage and release of Ii from class II MHC α/β/Ii trimers by cathepsin B, which has been shown by others to colocalize with class II MHC molecules in intracellular compartments and to generate antigenic peptide fragments. Cathepsin B at pH 5.0 cleaved and released Ii from class II MHC α- and β-chains. Cathepsin B digested Ii from α- and β-chains in a dose-dependent fashion, yielding 23-, 21-, and 10-kDa fragments. Blockage of cathepsin B activity with leupeptin restored the 2D(nonequilibrium pH gradient gel electrophoresis/SDS) PAGE patterns of Ii and sialic acid-derivatized forms of Ii seen without the protease. The fragmentation pattern of cathepsin D treatment was different from that of cathepsin B, yielding 25-kDa intermediates.
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M3 - Article
VL - 146
SP - 3877
EP - 3880
JO - Journal of Immunology
JF - Journal of Immunology
SN - 0022-1767
IS - 11
ER -