title: Altered cleavage site preference of a proteolytic antibody light chain induced by denaturation.
abstract: A recombinant antibody light chain (L chain) maintained under non-denaturing conditions displayed preferential cleavage of synthetic peptides conjugated to methylcoumarinamide (MCA) on the C-terminal side of Arg and Lys residues. The same L chain renatured from a denaturing solvent (guanidine hydrochloride) acquired the capability of cleaving Tyr-MCA and Leu-MCA bonds, and its ability to cleave MCA linked to basic residues was decreased. The altered cleavage preference was accompanied by a conformational transition in the protein, evident from the fluorescence emission spectra. These observations suggest the feasibility of redirecting the cleavage specificity via alterations in the conformation of proteolytic antibody combining sites.
authors.affiliation: University of Nebraska Medical Center, Department of Anesthesiology and Eppley Cancer Research Institute, Omaha 68198-6830, USA.
authors.forename: M
authors.initials: M
authors.lastname: Sun
authors.forename: S
authors.initials: S
authors.lastname: Paul
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017151:Antibodies, Catalytic / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D000911:Antibodies, Monoclonal / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D001665:Binding Sites; D007147:Immunoglobulin Light Chains / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D007700:Kinetics; D051379:Mice; D009842:Oligopeptides / Q000737:chemistry; D010447:Peptide Hydrolases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D011489:Protein Denaturation; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D013050:Spectrometry, Fluorescence; D013379:Substrate Specificity
chemical_list: D017151:Antibodies, Catalytic; D000911:Antibodies, Monoclonal; D007147:Immunoglobulin Light Chains; D009842:Oligopeptides; D011994:Recombinant Proteins; D010447:Peptide Hydrolases