Tracing structural changes of the pH-dependent CRYDASH protein
Presentation Type
Abstract
Faculty Advisor
Yvonne Gindt
Access Type
Event
Start Date
25-4-2025 9:00 AM
End Date
25-4-2025 9:59 AM
Description
Vibrio Cholerae Cryptochrome-1 (VcCRY-1) is a CRY-DASH protein that is part of the Cryptochrome/Photolyase family of (CPF) of flavoproteins. The CPF includes DNA Photolyase, which repairs UV-damaged DNA using light-driven electron transfer, Cryptochrome which signals for growth and development through blue light, and CRY-DASH which carries out both roles in vivo. Under high light intensity, CRY-DASH acts as a DNA photolyase and repairs UV-damaged DNA using blue light. Under low light intensity, it acts as a cryptochrome (i.e. a blue light signaling protein). The chemistry carried out by the protein is controlled by the oxidized state of the FAD cofactor. It appears that the formation of FAD from FADH can only occur if there is a nearby proton acceptor. It appears that substrate binding and pH changes prevent the formation of the fully oxidized FAD state. We test the availability of the proton acceptors by monitoring the kinetics of the oxidation of the FADH under different conditions. We also developed a method to test for major structural changes that may occur with pH and substrate binding using fluorescence anisotropy. Therefore, we will report on whether any structural changes have occurred.
Tracing structural changes of the pH-dependent CRYDASH protein
Vibrio Cholerae Cryptochrome-1 (VcCRY-1) is a CRY-DASH protein that is part of the Cryptochrome/Photolyase family of (CPF) of flavoproteins. The CPF includes DNA Photolyase, which repairs UV-damaged DNA using light-driven electron transfer, Cryptochrome which signals for growth and development through blue light, and CRY-DASH which carries out both roles in vivo. Under high light intensity, CRY-DASH acts as a DNA photolyase and repairs UV-damaged DNA using blue light. Under low light intensity, it acts as a cryptochrome (i.e. a blue light signaling protein). The chemistry carried out by the protein is controlled by the oxidized state of the FAD cofactor. It appears that the formation of FAD from FADH can only occur if there is a nearby proton acceptor. It appears that substrate binding and pH changes prevent the formation of the fully oxidized FAD state. We test the availability of the proton acceptors by monitoring the kinetics of the oxidation of the FADH under different conditions. We also developed a method to test for major structural changes that may occur with pH and substrate binding using fluorescence anisotropy. Therefore, we will report on whether any structural changes have occurred.
Comments
Poster presentation at the 2025 Student Research Symposium.