Determination of the quantum yields of Phrixotrix red emitting luciferase mutants with 6´-amino-analogs

• Grant number: 18/24889-0
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate (Direct)
• Start date: April 01, 2019
• End date: June 12, 2019
• Field of knowledge: Biological Sciences - Biophysics - Radiology and Photobiology
• Principal Investigator: Vadim Viviani
• Grantee: Vanessa Rezende Bevilaqua
• Supervisor: Yoshihiro Ohmiya
• Host Institution: Centro de Ciências e Tecnologias para a Sustentabilidade (CCTS). Universidade Federal de São Carlos (UFSCAR). Sorocaba , SP, Brazil
• Institution abroad: National Institute of Advanced Industrial Science and Technology, Tsukuba (AIST), Japan
• Associated to the scholarship: 15/06875-4 - Selection of Phrixothrix hirtus luciferase mutants (Coleoptera: Phengodidae) with higher catalytic constants and affinities for luciferin and ATP to the development of more efficient luciferases, BP.DD

Abstract

Beetle luciferases are responsible for the production of different bioluminescence colors from green to red using the same firefly D-luciferin. Some luciferin analogues such as 6´amino-analogues can extend the range of bioluminescence colors. Among several beetle luciferases that have cloned and been studied, Phrixothrix hirtus (PxRE) railroadworm luciferase is still the only one that naturally emits red light, displaying a sharp spectrum and high affinity for luciferin, being potentially useful for bioanalytical assays and bioimaging. However, this enzyme suffers of low quantum yield (15%) and stability when compared to green emitting luciferases (40-60%). Recently we have found that, among all beetle luciferases, P. hirtus red emitting luciferase displayed the highest bioluminescence activities and most red-shifted spectra with Molpholil-LH2 (634 nm) and Pirrolidil-LH2 (644 nm). To better understand why this enzyme displays higher bioluminescence activity with these analogues, we plan to determine the quantum yield of this luciferase, its mutants and comparatively other beetle luciferases with 6´-amino-analogues. (AU)