A human germ line antibody light chain with hydrolytic properties associated with multimerization status.
Antibodies with nucleophilic or catalytic properties often have these characteristics encoded in their germ line genes. Because hydrolytic activity has been reported to be associated with light chain V regions, we have begun an analysis of germ line light chain proteins that could be the basis for affinity maturation into hydrolytic or other reactive antibodies. We produced the germ line A18b light chain and characterized its hydrolytic, nucleophilic, and tertiary structural activities. This light chain was purified to >99% purity and found to hydrolyze aminomethylcoumarin-peptide and larger protein substrates and bind a fluorophosphonate probe. Mutation of putative catalytic residues only resulted in loss of activity of a tetrameric but not dimeric form of the light chain. These biochemical properties provide a framework for understanding the structure-function relationships of germ line antibodies.
Integrigen, Incorporated, Novato, California 94949, USA.
Vikram
V
Sharma
William
W
Heriot
Kirk
K
Trisler
Vaughn
V
Smider
D000906:Antibodies / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017151:Antibodies, Catalytic / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D000915:Antibody Affinity; D000918:Antibody Specificity; D015153:Blotting, Western; D020134:Catalytic Domain / Q000235:genetics; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D004591:Electrophoresis, Polyacrylamide Gel; D005854:Germ Cells / Q000276:immunology / Q000378:metabolism; D006801:Humans; D006868:Hydrolysis; D007147:Immunoglobulin Light Chains / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008958:Models, Molecular; D009154:Mutation; D011485:Protein Binding; D055503:Protein Multimerization; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry / Q000276:immunology / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000737:chemistry / Q000378:metabolism
D000906:Antibodies; D017151:Antibodies, Catalytic; D007147:Immunoglobulin Light Chains; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha