Date of Award

Fall 12-17-2016

Degree Type

Thesis

Degree Name

Master of Science - Biotechnology

Department

Biology

First Advisor

Dr. Beatrice Clack

Second Advisor

Dr. Rebecca Parr

Third Advisor

Dr. Odutayo Odunuga

Fourth Advisor

Dr. Daniel Bennett

Abstract

Eurygaster integriceps Puton (Sunn pest) is the most damaging insect pest of wheat in areas of North Africa, Eastern Europe and Western and Central Asia. Sunn pest injects an enzyme characterized as a prolyl endylprotease (spPEP) into wheat grains that digests the gluten protein (Darkoh et al., 2010). Previous studies have shown that casein peptides generated by Lactobacillus species have inhibitory effects on human (hPEP) and bacterial prolyl endoproteases (bPEP) which makes casein a good natural candidate to inhibit spPEP. Developing biopesticides for food products from αS1 casein is complicated due to some allergenic amino acid sequences. Ruiter et al (2005) identified a non-allergenic peptide region on αS1 casein that includes a previously identified inhibitory sequence (LNENLLRFFVAPFPEVFG) to hPEP (Jeanneret, 2011). The Objective of this study was to produce 16 recombinant peptides derived from αS1casein of varying lengths and varying placement of the non-allergenic inhibitory sequence. The inhibitory region is positioned at 0, 10, 20 and 30 amino acids from either N’ terminal or C-terminal end. Each of the peptides were cloned into pET15b for expression with a His tag for purification and thrombin site for removal of His-tag Peptides were incubated with either hPEP or spPEP in the presence of the substrate GPpNA. We report the inhibition of both enzymes based on size and placement of the inhibitory sequence.

Creative Commons License

Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.

Available for download on Wednesday, December 15, 2021

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