Elastin-like polypeptides (ELPs) are tunable, thermoresponsive biopolymers with promising applications in biomedicine and tissue engineering. This thesis presents the design, expression, and thermal characterization of a genetically engineered ELP construct, GFP-17x, composed of 17 pentapeptide repeats of a neutral, hydrophilic motif (N11V4) fused to superfolder Green Fluorescent Protein (sfGFP). The study investigates how protein concentration, ionic strength, and thermal history affect phase transition behavior, coacervate stability, and irreversible aggregation. Using UV-VIS spectroscopy and dynamic light scattering, a strong inverse loglinear relationship between protein concentration and transition temperature (Tt) was confirmed, consistent with classical ELP systems. Salt titration with ammonium sulfate revealed a decrease in Tt, promoting hydrophobic collapse and phase separation. However, unlike many ELPs, GFP-17x displayed irreversible aggregation at temperatures ≥45°C, even in the absence of salt. DCR time-course analysis demonstrated a progressive decline in fluorescence signal, indicating coarsening and sedimentation of aggregated structures. Post-heating centrifugation revealed insoluble white precipitates, characteristic of thermally trapped aggregates. Further investigation suggests that the observed irreversible behavior may be associated with the presence of asparagine residues in the ELP sequence. The strong hydrogen-bonding propensity of asparagine could promote the formation of amyloid-like vii aggregates at elevated temperatures, potentially destabilizing the native β-barrel structure of GFP. Such destabilization may lead to chromophore unfolding and a subsequent loss of fluorescence, indicating a possible coupling between ELP phase separation and GFP structural integrity. These findings underscore the delicate balance between chain length, hydrophilicity, and guest residue chemistry in modulating ELP behavior. GFP-17x serves as a model for short, neutral ELPs that exhibit thermal hysteresis and aggregation beyond their Tt. This knowledge provides a foundation for designing next-generation bioinks and scaffolds with improved thermal stability, reversibility, and functional reliability. Future work will focus on length-extended N11V4 constructs, rheological studies, computational simulations, and validation in tissue-engineered systems