Potential sites for processing of the human invariant chain by cathepsins D and E.
Seven peptides of 15-30 amino acid residues were synthesized that covered almost the entire sequence of the lumenal domain of the human invariant chain (Ii), and their hydrolysis by cathepsins D and E was investigated. Two sites were identified that were very susceptible to such cleavage. One site, the Leu174-Phe175 bond, was cleaved by both cathepsins, and the other site, the Met99-Gln100 bond, was specifically cleaved by cathepsin E. These two sites could be the sites at which native Ii is cleaved by aspartic proteinases. The cleavage of the Met99-Gln100 bond by cathepsin E might be important in the inactivation of Ii and its functional derivatives.
Kageyama
T
T
Department of Cellular and Molecular Biology, Kyoto University, Inuyama, Japan.
Yonezawa
S
S
Ichinose
M
M
Miki
K
K
Moriyama
A
A
D000595:Amino Acid Sequence; D000818:Animals; D015703:Antigens, CD / Q000737:chemistry / Q000378:metabolism; D000944:Antigens, Differentiation, B-Lymphocyte / Q000737:chemistry* / Q000378:metabolism*; D002402:Cathepsin D / Q000378:metabolism*; D020059:Cathepsin E; D002403:Cathepsins / Q000378:metabolism*; D000882:Haplorhini; D000949:Histocompatibility Antigens Class II / Q000737:chemistry* / Q000378:metabolism*; D006801:Humans; D007421:Intestine, Small / Q000201:enzymology; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000737:chemistry; D013154:Spleen / Q000201:enzymology
D015703:Antigens, CD; D000944:Antigens, Differentiation, B-Lymphocyte; D000949:Histocompatibility Antigens Class II; D046911:Macromolecular Substances; D010446:Peptide Fragments; C045084:invariant chain; D002403:Cathepsins; D020059:Cathepsin E; D002402:Cathepsin D