Author ORCID Identifier
0000-0001-6704-6116
Biosketch
G. Vijay has recently been awarded a doctoral degree by SASTRA. Prior to enrolling in the Ph.D. program, he had obtainedanM.Tech.in Biotechnology and Biochemical Engineering from IIT Kharagpur,a B.Tech. in Chemical Engineering fromBharathidasan University, andan M.B.A.in Operations Management from IGNOU. During his professional career, he has been associated with research institutions, the biopharmaceutical industry, and entrepreneurial ventures. He served as a CDFD-IKP Fellow at the Centre for DNA Fingerprinting and Diagnostics, worked in program management in the Biologics Division at Dr. Reddy’s Laboratories, andcontributed as a biosimilar scientist at Wockhardtbeforetransitioning to entrepreneurship. His academic training, together with 22 years of post-qualification professional experience, has provided him with a strong interdisciplinary foundation in biotechnology, bioprocess engineering, and business management.His areas ofacademic and professional competenceincludemolecular cloning, metabolic engineering, bioprocess development, scale-up & technology transfer and strategic planningfor bio-business.He ispresentlytheManaging Partner at Bionary Consulting, Tamil Nadu, where he is involved in biotechnology consulting, industry collaboration, and strategic initiatives in the life sciences sector.
Date of Award
21-7-2026
Document Type
Thesis
School
School of Chemical & Biotechnology
Programme
Ph.D.-Doctoral of Philosophy
First Advisor
Dr.V.Ponnusami
Keywords
Thrombosis, Streptokinase, Immunogenicity, Biotherapeutics, Plasminogen activator
Abstract
Thrombotic disorders such as myocardial infarction, ischemic stroke, pulmonary embolism and deep vein thrombosis remain major causes of mortality and disability worldwide, creating a continuing need for effective, safe and affordable thrombolytic therapy. Streptokinase is one of the most widely used plasminogen activators because of its activity, low cost and broad availability. However, its wider clinical utility is limited by high immunogenicity, allergic reactions, neutralizing antibody formation and poor suitability for repeat administration. This thesis aimed to develop novel streptokinase-derived plasminogen activators by identifying smaller functional fragments that retain thrombolytic activity while potentially reducing immunogenicity.
A literature-guided fragment-based strategy was employed to design ten streptokinase fragments based on known structural and functional regions of the native protein. These fragments were cloned, expressed in E. coli, and evaluated for plasminogen activation using qualitative caseinolytic plate assays and quantitative chromogenic assays. To support experimental findings, molecular modelling of the streptokinase-plasminogen complex, interface contact analysis, and residue-level mapping were performed to identify domains and residues critical for productive plasminogen binding.
Among the engineered fragments, F1 (1-300), F6 (1-173), and F10 (130-414) retained substantial plasminogen activation activity, with F1 and F6 showing the strongest overall performance relative to full-length streptokinase. Computational analysis indicated that the N-terminal region of streptokinase contains major interaction hotspots essential for functional activation, while the C-terminal region contributes stabilizing interactions.
Immunogenicity was evaluated using western blotting, ELISA-based immunoreactivity assays, rabbit immunization experiments, and immunoinformatic prediction. The results demonstrated that fragments F1 and F6 exhibited reduced immunoreactivity compared with native streptokinase while preserving meaningful functional activity, supporting the hypothesis that selective truncation can improve the balance between activity and antigenicity. A production cost analysis using standard recombinant fermentation and purification workflows further suggested that the shortlisted fragments, particularly F6, could be produced at a potential cost advantage compared with several currently marketed thrombolytics. Overall, this study establishes that rationally designed streptokinase fragments can serve as promising lead molecules for developing affordable and lower-immunogenic plasminogen activators, and it provides a strong basis for future preclinical optimization and therapeutic translation.
Recommended Citation
G, Vijay Mr, "Development of novel Plasminogen activators from fragments of Streptokinase enzyme" (2026). Theses and Dissertations. 224.
https://knowledgeconnect.sastra.edu/theses/224