Design and Characterize a Mutation [C131S] on sFGF1 of the sFGF1-FGF2 Dimer

Date of Graduation

5-2026

Document Type

Thesis

Degree Name

Bachelor of Science in Chemistry

Degree Level

Undergraduate

Department

Chemistry & Biochemistry

Advisor/Mentor

Thallapuranam, Suresh

Committee Member

Sakon, Josh

Second Committee Member

Walker, Kate

Abstract

Fibroblast Growth Factors (FGF) are biologically important proteins as they participate in various cellular processes such as cell proliferation, regeneration, regulation, differentiation, and angiogenesis. There are twenty-three different fibroblast growth factors that are divided into seven sub-groups. The Wild Type Fibroblast Growth Factor 1 (wtFGF1) is a part of the first sub-group and is classified as an acidic growth factor which can bind to all FGF receptors (FGF-R). FGF1 contains cell proliferation properties. Super FGF 1 (sFGF1) is an engineered and patented, more stable and efficient version of the wtFGF1 with little heparin binding affinity. Fibroblast Growth Factor 2 (FGF2) is part of the second sub-group and is a basic growth factor that contains angiogenic properties. FGF1 and FGF2 can be bound via glycine linker to form a heterodimer FGF1-FGF2. This dimer has already been characterized in previous research and has a higher biological activity and thermal stability compared to either FGF1 or FGF2 alone. Heparin has an overall negative charge while FGF1 has an overall positive charge. Both FGF1 and FGF2 bind tightly to heparin despite their different sequences and properties. Cysteine and serine are both polar uncharged amino acids at a neutral pH. Cysteine 131 on sFGF1 of the sFGF1-FGF2 dimer is located peripherally and is exposed to the solvent which is susceptible to oxidation and can form intermolecular disulfide bonds. The formation of disulfide bonds can possibly inactivate or depress the activity of the dimer. This project was concerned with mutating Cysteine 131 to Serine to observe the effects of this replacement on the stability and cell proliferation of the sFGF1-FGF2 dimer. The wild type and mutated heterodimer were expressed through E. coli and purified by affinity chromatography via heparin Sepharose column. In investigating the secondary and tertiary structures, site mutagenesis did not change the structures. Additionally, the mutated dimer showed resistance to trypsin and thrombin as well as an increased thermal stability. The increased cell proliferative effects of this mutation were significant as well. Future work may be directed at increasing the heparin binding affinity of sFGF1 of the dimer to further its biotherapeutic potential.

Keywords

Fibroblast Growth Factors; FGF; Super FGF1; FGF1/FGF2; Chronic Wounds; Cell Proliferation

This document is currently not available here.

Share

COinS