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Expert has spent the majority of his professional career developing and refining the use of chemical
engineering techniques to design biochemical reactors holding enzymes and microbial cells. Expert is an Anson
Marston Distinguished Professor Emeritus in Employer's Chemical Engineering program.

Expert works in the general area of biochemical engineering, and more specifically to mutate enzymes such as
glucoamylase and the cellulases that hydrolyze polysaccharides, to determine sugar structures by computational
molecular mechanics, to computationally dock oligosaccharides into the active sites of hydrolytic enzymes, and to use
liquid and gas chromatography and mass spectroscopy to identify and quantify components of agricultural and food
processing residues.

He is an expert in applied enzymology, related process development, and scale-up. He works extensively in enzyme kinetics, and has published on enzyme immobilization. He has expertise in the characterization of soluble and immobilized enzyme function, specifically enzyme kinetics. He has a great deal of experience in the formulation of enzyme rate equations to design bioreactors in incorporating effects of temperature, pH, and diffusion limitation on enzyme activity and stability.

Expert is familiar with the structure and function of carbohydrates, specifically monsaccharide and disaccharide conformation calculated by molecular mechanics algorithms. He has experience with the production of sugars and corn syrup from malto-, cello-, and xylodextrins and their corresponding polysaccharides by enzyme-catalyzed hydrolysis with amylases, cellulases, and xylanases.

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Expert has extensive experience in the use of gas-liquid and high-performance liquid chromatography to separate sugars and oligosaccharides, determine the chromatographic separation mechanisms, correlate the molecular properties with capacity factors, and the identification of hydroxylated organic molecules. Many food processing and agricultural residues have components that are of potential commercial interest. However, most residues are not found in central locations and others are either solid or have so many components that separation of those that could be sold at a profit is economically infeasible. Expert has been analyzing three liquid residues that are centrally located. Stillage, the bottoms from the distillation of ethanol, is a major byproduct that at present is fed to animals after concentration, an expensive and energy-intensive step. Gas chromatography of the derivatized mixture followed by mass spectroscopy to determine the organic composition from various sources such as corn, cane sugar molasses, citrus waste, and sweet cheese whey showed that there were no valuable components in sufficiently high concentrations to be economically separated. Similar analysis of the alkaline washes of canola, coconut, corn, cottonseed, peanut, soybean, and sunflower oils has identified a number of phosphatide fragments that can be separated by ion-exchange liquid chromatography for use as specialty raw materials and laboratory chemicals. At present he is investigating fluid from cattle rumens.

Expert is experienced in the use of mutagenesis, specifically site-directed, cassette, and random mutagenesis, to change the glucoamylase gene so that the expressed enzyme has different thermostability, selectivity, and optimal pH. He has used mutagenesis to determine the function of amino acid residues in the active site. He has extensive experience in the deletion of portions of the gene to determine the function of the glycosylated domain of glycoamylase. Expert has subjected glucoamylase to site-directed mutagenesis, where individual amino acid residues of the enzyme are changed by recombinant DNA technology. This, with the help of the three-dimensional structure of the enzyme, has yielded a number of major advances: 1) identification of one of the two acidic amino acids that catalyze the actual hydrolysis of the glucosidic bonds that link the D-glucosyl residues of starch and maltooligosaccharides; 2) a determination of how other amino acid residues in glucoamylase's active site bind glucosyl residues in the substrate; 3) substantial increases in enzyme thermostability; 4) significant increases in glucoamylase selectivity for glucose rather than byproduct formation; 5) a greater understanding of how glycosylation of glucoamylase affects its thermostability and secretion. Expert is also studying glucoamylase by advanced modeling methods, using available three-dimensional structures as a template. Hydrophobic cluster analysis allows the alignment of all glucoamylases for which an amino acid sequence is available and from this he can obtain the secondary structures of each. It is possible to infer the three-dimensional structures of all sequenced glucoamylases using other computational techniques. Finally, Monte Carlo simulation using the three-dimensional structure of the enzyme and optimal conformations of different actual and potential substrates yields optimal docked enzyme-substrate conformations.