MICHAEL R. SIERKS

Assistant Professor

Description of Research:


My research interests basically deal with getting proteins to do what we want them to. By utilizing various protein engineering techniques, we can study and manipulate the structural and functional relationships of proteins and their interactions with ligands. The ability to alter or create various protein functions can be utilized to study or control a wide variety of important biological processes.

One area we are currently studying is how to modify activity toward specific carbohydrates. Carbohydrates are involved in a variety of critical cellular processes such as inflammation, viral adhesion and tumor formation, so having the ability to specifically alter the structures involved in these events may enable us to eventually control them. Two different approaches are being utilized to generate specific protein/carbohydrate interactions. In the first approach, we are attempting to generate catalytic antibodies which can synthesize or hydrolyze various carbohydrate structures. The objective is to screen a library of artificially constructed antibody binding domains for activity toward a particular carbohydrate substrate by using a suitable transition-state analog as an antigen. This technique bypasses the need for generating monoclonal antibodies. The ultimate goal is to design catalytic antibodies which can synthesize or hydrolyze specific carbohydrate structures either in vivo or in vitro. The second approach to studying protein/carbohydrate interactions involves utilizing site-directed mutagenesis to define and improve the function of carbohydrase enzymes. Individual substitutions of functionally important amino acid residues produce changes in enzyme catalytic and binding activity which can be analyzed by steady-state and presteady-state kinetic studies. This information along with available structural information is then used to define catalytic mechanisms and to suggest routes to improve either the synthesis or hydrolysis of specific carbohydrate structures.

Purification is one of the major problems encountered in producing a fermentation product. We are currently studying the feasibility of using artificially generated antibodies as an inexpensive, simple method to purify protein products or remove individual contaminants from a product stream. The goal is to isolate antibodies which can purify a specific protein from closely related proteins, including the ability to isolate a specific isoform, optical isomer, glycosylated form or individually mutated protein. The antibodies can be selected or tailored to purify proteins at any given product stream conditions including different pHs, ionic strengths and temperatures.

Alzheimer's Disease (AD) is one of the most debilitating diseases affecting the elderly population. We are currently trying to develop a diagnostic tool and possible treatment for AD by isolating artificial antibodies specific for the §-amyloid peptide which forms plaque tissue around the neurons. The goal is to block and remove the §-amyloid peptide before it can aggregate and form plaques and testing this as a potential method for stopping the onset of AD.

Publications:


Research Group
Jennifer Olkowski

o Michael R. Sierks