Dissertation/Thesis Abstract

Investigating the Catalytic Role of Lysine Residue 41 in Pancreatic Ribonuclease A
by Alade, Ayoade Nathaniel, M.S., California State University, Long Beach, 2017, 71; 10603029
Abstract (Summary)

Understanding enzyme catalysis is one of the major goals in biology. Ribonuclease A (RNase A) is a key system to understanding protein structure and function provides an attractive system to investigate the catalytic role of active site interactions. Crystal structures show a lysine residue (Lys41) situated in the RNase A active site, and mutagenesis studies suggest this residue is important for catalysis. To evaluate the catalytic importance of the Lys41-phosphate interaction, double mutant cycle analysis was used. Individual mutation of lysine to arginine (K41R) and substitution of a phosphate oxygen with sulfur led to ∼350 and ∼100-fold decrease in kcat/KM, respectively. However, in the K41R background, substitution of the same oxygen with sulfur decreased activity by a similar amount (within 2-fold) as it did with the wild-type enzyme. This result provides evidence that functional interaction between Lys41 and the phosphate backbone of RNA substrates may not be solely limited between the two groups.

Indexing (document details)
Advisor: Schwans, Jason P.
Commitee: Bhandari, Deepali, Weers, Paul M.M.
School: California State University, Long Beach
Department: Chemistry and Biochemistry
School Location: United States -- California
Source: MAI 56/05M(E), Masters Abstracts International
Source Type: DISSERTATION
Subjects: Molecular biology, Chemistry, Biochemistry
Keywords: Enzyme catalysis, Enzyme kinetics, Enzymology, Phosphorothioate, Ribonuclease a, Site-directed mutagenesis
Publication Number: 10603029
ISBN: 978-0-355-23017-8
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