Accession Number : ADA306873
Title : Design of Metal-Detecting Antibodies.
Descriptive Note : Final rept. 1 Apr 91-31 Mar 94,
Corporate Author : SCRIPPS RESEARCH INST LA JOLLA CA
Personal Author(s) : Getzoff, Elizabeth D. ; Roberts, Victoria A.
PDF Url : ADA306873
Report Date : 09 APR 1996
Pagination or Media Count : 7
Abstract : We have designed metal ion biosensors through the template-based incorporation of metal-binding sites into an antibody scaffold. We constructed a high-resolution three-dimensional model of the variable domain of the catalytic antibody NPN43C9 based on our antibody structural database. By transplanting metal-binding templates from metelloenzymes into the antibody structural model, we identified potential metal-binding sites within the antigen-binding pocket, where bound metal could be detected by spectral changes of the antibody or of bound antigen analogs. Three distinct metal-binding sites, one with ligands in the VL domain, one with ligands in the VH heavy domain, and one with ligands in both domains, were made collaboratively in the Benkovic laboratory by site-directed mutagenesis and shown spectroscopically - to bind metal ions as predicted. These results demonstrated the success of our design approach, the versatility bf the antibody structure for metalloprotein design, and the validity of the three-dimensional model. One site shows selectivity for Cu(II) over Zn(II), while the other two sites display a more unusual preference for Zn(II) over Cu(II). Thus, we have designed metal-binding sites having different metal specificities into a single antibody. A panel of such mutants proteins, based on a single antibody, could act as a biosensor for multiple metal ions.
Descriptors : *METALS, *TEMPLATES, *ANTIBODIES, *BIOLOGICAL DETECTION, *METAL COMPOUNDS, DATA BASES, IONS, DETECTORS, MODELS, STRUCTURAL PROPERTIES, ENZYMES, PROTEINS, SITES, HIGH RESOLUTION, MUTATIONS, DISPLAY SYSTEMS, VARIABLES, THREE DIMENSIONAL, SPECTRA, COPPER, LIGANDS, ZINC, ANALOGS, ANTIGENS, METALLOGRAPHY, PROTEINS(CONJUGATED).
Subject Categories : Biochemistry
Radiation and Nuclear Chemistry
Metallurgy and Metallography
Distribution Statement : APPROVED FOR PUBLIC RELEASE