Faithin Omaha eBook Collection

Download or read book Biosensor Design: Combinatorial and Rational Approaches written by and published by . This book was released on 1998 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This ASSERT proposal supports graduate assistants working on projects related to the parent grant, Molecular Approaches to Optical Biosensors, which proposes to optimize a carbonic anhydrase-based fluorescence biosensor for detecting metals. Our current goals were to use mutagenesis to prepare carbonic anhydrase variants with: (1) altered metal ion specificity by varying the size, geometry and chemical structure of direct and indirect metal ligands; and (2) increased protein stability by insertion of disulfide bonds. The metal ion specificity of CA variants with alterations in the histidines that coordinate the metal ion is altered significantly compared to wild-type. For example, the Cu/Zn affinity ratio varies from 1 for H119Q CAII to 10 for wild-type CAII to 6 x 10(exp 4) for H119N CAII. These variants should be useful for either preparing copper-specific sensors or for measuring multiple metal ions simultaneously using a CA-based biosensor. Furthermore, analysis of double cysteine variants indicates that the PAIRWISE potential is a good predictor of the strength of a novel disulfide bond, however, the destabilizing effects of cysteine substitutions on the native state and the stabilization of compact non-native states by the disulfide can override any stabilizing effect of the crosslink.