Presentation Title

Engineering Virus-Like Nanoparticles as Heparin Antagonists

Faculty Mentor

Andrew K. Udit, PhD

Start Date

23-11-2019 8:00 AM

End Date

23-11-2019 8:45 AM

Location

171

Session

poster 1

Type of Presentation

Poster

Subject Area

health_nutrition_clinical_science

Abstract

Heparin is a negatively charged polysaccharide that is routinely used as an anticoagulant. The only FDA approved reversal agent for heparin is protamine sulfate, which is acutely toxic and brings about adverse reactions in patients. This research explores the use of engineered virus-like particles (VLPs), derived from bacteriophage Qβ, as potent heparin antagonists that provide a better alternative to the toxic protamine. A two-plasmid system was used to make our VLPs, in which one plasmid with the wild-type coat protein, and another plasmid with a coat protein having a C- or N- terminal peptide extension, co-transform and express our “hybrid” VLPs. The resulting plasmids for the “hybrid” VLPs thus possess a certain-percentage of the non-wild-type peptide extensions with specifically engineered positively-charged sequences. Activated partial thromboplastin time (APTT) assay was used to show that these VLPs were effective at binding heparin and returning clotting time to normal. Heparin affinity chromatography showed that the proportion of coat protein with peptide extensions increased with ionic strength, indicating that VLPs with more heparin-binding peptides bound to the column more strongly. Overall, since VLPs do not cause irregular clotting unlike protamine, they present a safer alternative, and should be investigated further to for validation as a possible replacement for protamine.

This document is currently not available here.

Share

COinS
 
Nov 23rd, 8:00 AM Nov 23rd, 8:45 AM

Engineering Virus-Like Nanoparticles as Heparin Antagonists

171

Heparin is a negatively charged polysaccharide that is routinely used as an anticoagulant. The only FDA approved reversal agent for heparin is protamine sulfate, which is acutely toxic and brings about adverse reactions in patients. This research explores the use of engineered virus-like particles (VLPs), derived from bacteriophage Qβ, as potent heparin antagonists that provide a better alternative to the toxic protamine. A two-plasmid system was used to make our VLPs, in which one plasmid with the wild-type coat protein, and another plasmid with a coat protein having a C- or N- terminal peptide extension, co-transform and express our “hybrid” VLPs. The resulting plasmids for the “hybrid” VLPs thus possess a certain-percentage of the non-wild-type peptide extensions with specifically engineered positively-charged sequences. Activated partial thromboplastin time (APTT) assay was used to show that these VLPs were effective at binding heparin and returning clotting time to normal. Heparin affinity chromatography showed that the proportion of coat protein with peptide extensions increased with ionic strength, indicating that VLPs with more heparin-binding peptides bound to the column more strongly. Overall, since VLPs do not cause irregular clotting unlike protamine, they present a safer alternative, and should be investigated further to for validation as a possible replacement for protamine.