Molecular Microbiology & Biotechnology
Tel Aviv University
Gideon Fleminger, Professor, Molecular Microbiology & Biotechnology, Tel Aviv University, Israel
Structure-function relationships in Ca+2-binding proteins: We are engaged in the study of the conformational changes which occur in calmodulin upon binding of Ca+2 ions and target proteins. Our goal is to understand the mechanism of calmodulin activity via the stabilization, isolation and characterization of conformation-intermediates involved in the calmodulin activation process. In this study, we use a combination of biochemical, immunochemical and advanced separation techniques. Involvement of catalytic peptides in the evolution of biocatalysts under prebiotic conditions: In an attempt to understand how enzymes evolved at the prebiotic era, in absence of the ribosomal machinery, we developed an hypothesis of "substrate assisted and directed" synthesis of primitive biocatalysts. We were indeed able to prepare in the laboratory, under conditions that assumingly prevailed at the prebiotic era, using a substrate as a template, a compound which possessed catalytic activity towards the substrate. This compound was isolated, purified and identified as a metallo-peptide complex. The application of "Subsrate-directed" synthesis of catalytic peptides in Biotechnology is now being studied in my Lab. The role of lectins in biorecognition in lichens: The goal of this project is to study the role that lectins have in the mutual recognition between alga and fungi involved in lichen formation. Lectins were isolated and purified from several lichens and have been shown to direct the specific interactions that lead to lichen formation. The regulation of peptide activity by controlled proteolysis: This project involves the study of the enzymatic processes that lead to formation of endothelins from their precursor and to controled degradation of endothelins in Health and Desease. The physiological implications under normal and pathological situations are studied as well. Isolation and characterization of a bacterial titanium-binding proteins: A Rhodococcus which is capable of adsorption to titanium-rich particles in coal fly ash has been isolated as part of a project supported by the Israel Electric Company Company which aimed at the development of biological treatment of coal fly ash and the recovery of titanium and aluminum from it.. This bacterium was found to contain a unique titanium-binding protein on its surface. This protein is a subject of a study in our laboratory which aims at the elucidation of its properties and mode of action.
Wolf, T., Fleminger, G. and Solomon, B., - "Functional conformations of calmodulin: I. Preparation and characterization of conformational specific anti bovine calmodulin monoclonal antibody" - J. Mol. Recog. 8, 67-71 (1995).
Fleminger, G., Neufeld, T., Weinstock-Star, M., Litvak, M. and Solomon, B. - "Calcium-modulated conformational affinity chromatography - application to the purification of calmodulin and s100 proteins" - J. Chromatog. 597, 257-262 (1992).