Specific cleavage of immunoglobulin G by copper ions.
The hinge region of a recombinant-DNA-produced human IgG1 (Campath 1H) is specifically cleavable at a single copper-sensitive peptide bond, yielding a distinct fragment resolved by size-exclusion high-performance liquid chromatography. This novel metal ion-catalysed cleavage at slightly alkaline pH is inhibited by EDTA and its rate is reduced at slightly acidic conditions (pH 5-6) and accelerated by increasing concentrations of cupric ion and higher temperature. Complete cleavage was observed after incubation at pH 8 for 24 h with 1 mM CuCl2. Sequence analysis determined the cleavage site to be the Lys226-Thr227 bond in the hinge-region sequence DKTHT. Cleavage of other IgGs was observed to varying degrees, and specific cleavage of synthetic peptides containing this pentapeptide sequence was also observed.
Smith
M A
MA
Biotechnology Development Laboratories, Wellcome Research Laboratories, Beckenham, Kent, UK.
Easton
M
M
Everett
P
P
Lewis
G
G
Payne
M
M
Riveros-Moreno
V
V
Allen
G
G
D000074323:Alemtuzumab; D000911:Antibodies, Monoclonal / Q000737:chemistry / Q000378:metabolism; D061067:Antibodies, Monoclonal, Humanized; D000912:Antibodies, Neoplasm / Q000737:chemistry / Q000378:metabolism; D001665:Binding Sites; D002412:Cations; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D003300:Copper / Q000737:chemistry / Q000378:metabolism*; D004492:Edetic Acid / Q000737:chemistry; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007074:Immunoglobulin G / Q000737:chemistry* / Q000378:metabolism*; D008670:Metals / Q000737:chemistry / Q000378:metabolism; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism; D011489:Protein Denaturation; D013696:Temperature; D013997:Time Factors
D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D000912:Antibodies, Neoplasm; D002412:Cations; D007074:Immunoglobulin G; D008670:Metals; D010446:Peptide Fragments; D000074323:Alemtuzumab; D003300:Copper; D004492:Edetic Acid