Researchers Developed Targeted Protein Degrader PSIRC3
A new covalent PROTAC has demonstrated rapid and selective degradation of Bruton's tyrosine kinase.
Updated on Oct. 7, 2026 in Biotech
Scientists have engineered PSIRC3, a novel covalent PROTAC designed to target and break down Bruton's tyrosine kinase (BTK). This molecule achieves significant degradation levels by forming a covalent bond with a specific cysteine residue.
Why it matters
By facilitating the rapid removal of BTK proteins, this research offers a potential pathway for more effective therapies in conditions where BTK activity drives disease progression. The selective nature of the degradation mechanism helps minimize unintended interference with other cellular processes.
PSIRC3 achieves a sub-nanomolar DC50 of 0.75 nM and reaches maximum BTK degradation within 30 minutes. The agent successfully degrades over 80% of BTK in PBMCs and over 50% in splenocytes following a single administration.
The players
PSIRC3
This is a covalent PROTAC molecule specifically engineered to target and degrade Bruton's tyrosine kinase.
Bruton's tyrosine kinase
This protein is a critical enzyme in the B-cell receptor signaling pathway and acts as a common target for therapeutic interventions in various cancers.
The details
The efficacy of PSIRC3 relies on its ability to form a covalent bond with the Cys481 residue on the BTK protein. This action is highly specific, as the compound loses its degradative power when tested against the C481S BTK mutant.
Timeline
October 7, 2026: The research findings regarding PSIRC3 were published.
The Tech Race
The development of PSIRC3 advances the targeted protein degradation platform by enabling covalent attachment to specific protein residues. This evolution represents a shift from traditional inhibitor-based treatments toward more precise enzymatic removal technologies.
This development represents a technical breakthrough in drug design that may eventually lead to more potent and selective medical treatments for patients. Future applications will focus on translating these laboratory results into clinical methodologies for managing diseases linked to BTK activity.
The takeaway
The successful application of covalent bond formation in PROTAC design highlights a growing precision in molecular medicine. This approach provides a blueprint for scientists to target other proteins previously considered difficult to degrade with non-covalent methods.
Further reading
Learn more about the latest innovations in Biotech.
Source note: This article includes information reported by Nature.
