Keywords

Chloroplasts, Peptide antibiotics

Abstract

Retrocyclin-101 (RC101) and Protegrin-1 (PG1) are two important antimicrobial peptides that can be used as therapeutic agents against bacterial and/or viral infections, especially those caused by the HIV-1 or sexually-transmitted bacteria. Because of their antimicrobial activity and complex secondary structures, they have not yet been produced in microbial systems and their chemical synthesis is prohibitively expensive. Therefore, we created chloroplast transformation vectors with the RC101 or PG1 coding sequence, fused with GFP to confer stability, furin or Factor Xa cleavage site to liberate the mature peptide from their fusion proteins and a His-tag to aid in their purification. Stable integration of RC-101 into the tobacco chloroplast genome and homoplasmy were confirmed by Southern blots. RC-101 and PG1 accumulated up to 32-38% and 17~26% of the total soluble protein. Both RC-101 and PG1 were cleaved from GFP by corresponding proteases in vitro and Factor Xa like protease activity was observed within chloroplasts. Confocal microscopy studies showed location of GFP fluorescence within chloroplasts. Organic extraction resulted in 10.6 fold higher yield of RC 101 than purification by affinity chromatography using His-tag. In planta bioassays with Erwinia carotovora confirmed the antibacterial activity of RC101 and PG1 expressed in chloroplasts. RC101 transplastomic plants were resistant to TMV infections, confirming antiviral activity. Because RC101 and PG1 have not yet been produced in other cell culture or microbial systems, chloroplasts can be used as bioreactors for producing these proteins. Adequate yield of purified antimicrobial peptides from transplastomic plants should facilitate further pre-clinical studies

Notes

If this is your thesis or dissertation, and want to learn how to access it or for more information about readership statistics, contact us at STARS@ucf.edu

Graduation Date

2010

Semester

Summer

Advisor

Daniell, Henry

Degree

Master of Science (M.S.)

College

College of Medicine

Department

Molecular Biology and Microbiology

Format

application/pdf

Identifier

CFE0003199

URL

http://purl.fcla.edu/fcla/etd/CFE0003199

Language

English

Release Date

August 2010

Length of Campus-only Access

None

Access Status

Masters Thesis (Open Access)

Subjects

Dissertations, Academic -- Medicine, Medicine -- Dissertations, Academic

Download

Share

COinS