Molecular modeling of the stability of the interaction of Sunda porcupine (Hystrix javanica) quill protein homologs with vascular endothelial growth factor receptor 2 (VEGFR-2).

Porcupines (Hystrix spp.) are widely distributed rodents known not only for their ecological roles but also for their traditional medicinal applications. In Indonesia, quills from species like Hystrix javanica, Hystrix sumatraensis, and Hystrix brachyura are traditionally used to relieve pain and promote wound healing. Scientific studies have revealed that porcupine quills are rich in bioactive compounds, including keratin, peptides, flavonoids, and triterpenoids. Keratin, a structural protein abundant in epithelial cells extracted from porcupine quill, has been found to support various wound-healing processes, having antibacterial properties, and the ability to induce apoptosis in breast cancer cells. Meanwhile, the vascular endothelial growth factor receptor 2 (VEGFR-2) plays a crucial role in angiogenesis and tissue regeneration during the wound-healing process. This study employed exploratory structural bioinformatics to study the potential interaction between porcupine quill-derived homolog proteins and VEGFR-2 from our previous published work. Through protein-protein docking and molecular dynamics simulation, we predicted molecular recognition and binding affinity computationally. Keratin type II (P50446), Krt2 (B2RTP7), and Keratin isoform X1 (A0A6P5R3S8) demonstrated the most robust and stable interactions with VEGFR-2. Contrarily, Keratin type II (P04264) displayed comparatively greater structural fluctuations and weaker stability, suggesting less optimal and more flexible binding interactions with the receptor. Thus, this research provides preliminary hypothesis evidence of potential interactions between porcupine quill-derived proteins and VEGFR-2, supporting further experimental studies to determine whether these interactions have biological relevance in wound-healing processes.