Dept. of Biochemistry & Organic Chemistry
Research
Recombinatorial protein evolution in multivariate functional space
Proteins have an enormous potential to evolve for novel molecular functions in biological systems. By recombination of their structural elements new properties emerge that are optimized by molecular evolution under selection pressure. The redesign of proteins for desired functions is a promising emerging area in biotechnology.
Combinatorial protein chemistry can mimic natural evolution through recombination of genetic materials followed by selection of gene products, but can also add new dimensions by chemical semisynthesis, including nonbiological building blocks.
A major approach in the project is the generation of mutant libraries from which protein variants with valuable properties are isolated. The strategies involve both rational mutations of targeted sites and stochastic recombinations of evolving “quasi-species”. Recursive isolation of improved mutants followed by mutagenesis tailors proteins to function by means of molecular breeding. Important properties of the emerging proteins are studied and clusters of mutants with optimal evolutionary potential are identified in multidimensional factor space by means of multivariate analysis. The methods developed have broad general applicability in protein engineering.
Specific goals of the project include the design of recombinant enzymes for detoxication of environmental and occupational pollutants, catalysts for the stereospecific catalysis of fine chemicals, and biosensors of toxic molecules.
References:
Sofia Hederos, Kerstin S. Broo, Emma Jakobsson, Gerard J. Kleywegt, Bengt Mannervik and Lars Baltzer (2004) Incorporation of a single His residue by rational design enables thiol-ester hydrolysis by human glutathione transferase A1-1, Proc. Natl. Acad. Sci. USA 101 , 13163-13167.
Anna-Karin Larsson, Lars O. Emrén, William G. Bardsley and Bengt Mannervik (2004) Directed enzyme evolution guided by multidimensional analysis of substrate-activity space, Protein Eng. Design Select. 17 , 49-55.
Bengt Mannervik, Lars O. Hansson and William G. Bardsley (2003) Exploring the functional space of combinatorial mutant libraries for the directed evolution of novel enzyme activities, in "Enzyme Functionality: Design, Engineering and Screening" (A. Svendsen, ed.), pp. 443-460 Marcel Dekker, New York.
Xiaojun Ren, Per Jemth, Philip G. Board, Guimin Luo, Bengt Mannervik, Junqiu Liu, Kun Zhang and Jiacong Shen (2002) A semisynthetic glutathione peroxidase with high catalytic efficiency: Selenoglutathione transferase, Chem. Biol. 9 , 789-794.
Pär L. Pettersson, Ann-Sofie Johansson and Bengt Mannervik (2002) Transmutation of human glutathione transferase A2-2 with peroxidase activity into an efficient steroid isomerase, J. Biol. Chem. 277 , 30019-30022.
Kerstin Broo, Anna-Karin Larsson, Per Jemth and Bengt Mannervik (2002) An ensemble of Theta class glutathione transferases with novel catalytic properties generated by stochastic recombination of fragments of two mammalian enzymes, J. Mol. Biol. 318 , 59-70.