Design of a specific human leukocyte elastase inhibitor based on ovomucoid third domains

Richard Wynn, Purdue University

Abstract

The general objective of this work was to contribute to a large set of association equilibrium constants (Ka) for ovomucoid third domains and to design specific inhibitors using the data set as a knowledge base. Rationalization of the data is often provided by analysis of several available x-ray crystal structures of ovomucoid third domains either free or complexed to a serine proteinase. Interpretation of the data base has led to two simplifying assumptions. First, residues in the inhibitor which do not contact enzyme have no effect on Ka. This assumption holds in 90% of the cases tested. Second, the effect of an amino acid substitution at any particular position is supposed to be independent of the remaining inhibitor sequence. While this assumption holds in a majority of the cases tested, large errors do occur. Failure of this assumption may lead to errors in the prediction of designed inhibitor Ka values. Finally, a specific inhibitor was designed for Human Leukocyte Elastase and chemically synthesized. The experimental Ka values for this inhibitor show that considerable specificity was obtained. Furthermore, several other inhibitor designs will be presented. Future production of these designs may result in highly specific inhibitors for other serine proteinases.

Degree

Ph.D.

Advisors

Laskowski, Purdue University.

Subject Area

Biochemistry|Biophysics

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