Site directed mutagenesis mutation

P204F <7> (<7> site-directed mutagenesis, mutation in the hinge region of the enzyme, which plays a role in protein folding during catalysis, less well folded with considerable loss of secondary and tertiary structure, no activity [59]) [59]... 

D282A <4> (<4> isozyme PDK2, site-directed mutagenesis, mutation of conserved amino acid, no activity, not able to bind ATP but the protein substrate [24]) [24]... 

A novel succinate pathway in E. coli was discovered in the NZNlll mutant. Using site-directed mutagenesis, mutations were made in malate dehydrogenase, which catalyzes the interconversion of malate and oxalacetate. These mutant malate... 

Ser L223 is in the path with the shortest cutoff distance this suggests its involvement in proton transfer to Qb- Ser L223 is close to Asp L213 from which it presumably receives a proton (possible mechanisms for this transfer are discussed in ref. 7). Transfer by means of this pathway is supported by results from site-directed mutagenesis. Mutation of Ser L223 to Ala blocked electron and proton transfer, while mutation to the functionally similar threonine showed essentially no effect. 

The specific role of each amino acid residue for the function of the protein can be tested by making specific mutations of the residue in question and examining the properties of the mutant protein. By combining in this way functional studies in solution, site-directed mutagenesis by recombinant DNA techniques, and three-dimensional structure determination, we are now in a position to gain fresh insights into the way protein molecules work. 

In molecular pharmacology research an indirect proof of a structural model is possible by functional examinations, e.g., by molecular biological experiments. Well-selected site directed mutagenesis and their functional characterization allows confirmation or rejection of a molecular protein model. The process is organized as an iterative procedure, where the biological answer of suggested mutations is used to refine the model. The iteration continues until the model... 

Site directed mutagenesis of His223 of PGII with subsequent analysis of the mutated PGII revealed that His223 is essential for catalysis. 

Lavoie, T. B., Drohan, W. N. and Smith-Gill, S. J. (1992), Experimental analysis by site-directed mutagenesis of somatic mutation effects on affinity and fine specificity in antibodies specific for lysozyme , f. Immunol., 148, 503-513. 

Changing the amino acid sequence of the cloned receptors by mutating nucleotides within the receptor cDNAs has proven to be an effective mechanism by which to identify structural features of the receptors responsible for their unique functional properties. In particular, site-directed mutagenesis has been employed to determine the ligand binding domains of each opiate receptor. 

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