Date of Award

Fall 12-5-2025

Track

Chemistry

Degree Type

Thesis

Degree Name

Master of Science in Chemical Sciences (MSCB)

Department

Chemistry

Committee Chair/First Advisor

John Haseltine

Committee Member

Carol Chrestensen

Committee Member

Daniela Tapu

Abstract

An analysis of geometry in known serine protease crystal structures was conducted to give insight into the structural similarities of the ‘oxyanion holes’ in trypsin and subtilisin. The mean conformations of segments forming the oxyanion holes of these enzymes indicated that almost all of their relevant torsions are within 20° of creating ideal, extensive orbital alignments throughout their sequences. We propose that these alignments are available for dynamic through-bond electronics and may accommodate transient oxyanionic character during the formation and hydrolysis of the acyl-enzyme intermediate in proteolysis. We also carried out ab initio modeling using the Spartan software to analyze charge accommodation in various oligomeric molecular backbones as a function of strand length, heteroatom and pi-bond content, and conformation. In doing so, we were able to explore the possible importance of these factors in charge accommodation. In the crystal structures, we also considered the possibility of dynamic orbital splicing between the enzymes and their substrates. This allows us to develop a new rationale for the geometric similarities in serine proteases and speculate on active-site dynamics during the proteolytic mechanism.

Available for download on Wednesday, December 15, 2027

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