A temperature‐driven, reversible helical handedness inversion in peptaibol analogs tuned by the C‐terminal capping moiety

DOI: 10.1002/cbic.201900235

Authors: Marta De Zotti (University of Padova) , Victoria N. Syryamina (Institute of Chemical Kinetics and Combustion, RAS Novosibirsk; Novosibirsk State University) , Rohanah Hussain (Diamond Light Source) , Edoardo Longo (Free University of Bozen-Bolzano) , Giuliano Siligardi (Diamond Light Source) , Sergei A. Dzuba (Institute of Chemical Kinetics and Combustion, RAS Novosibirsk) , Lorenzo Stella (University of Rome Tor Vergata) , Fernando Formaggio (University of Padova)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Chembiochem

State: Published (Approved)
Published: May 2019
Diamond Proposal Number(s): 13463 , 11528 , 14298

Abstract: Trichogin is a natural peptide endowed with antimicrobial and antitumor activity. A member of the peptaibol family, trichogin possesses a C‐terminal aminoalcohol. In the past, we substituted that moiety with a methyl ester for synthetic purposes and realized that this apparently slight modification causes great changes in the peptide bioactivity. Aiming at understanding the reasons behind such observations, we performed a detailed spectroscopic study on a number of trichogin analogs. In the present manuscript, we compare the data obtained from synchrotron radiation circular dichroism, NMR and fluorescence spectroscopy in organic solvents at cryogenic temperatures with those independently acquired by electron paramagnetic resonance spectroscopy at 80K. We reveal unambiguously the presence of a reversible, temperature‐driven screw‐sense interconversion from right‐handed to left‐handed helix that is determined by the C‐terminal capping moiety. Our data demonstrate for the first time the key role of a C‐terminal methyl ester in promoting peptide screw‐sense inversion.

Journal Keywords: antimicrobial peptide; conformational transition; C-terminal methyl ester; screwsense switch; synchrotron radiation circular dichroism

Subject Areas: Biology and Bio-materials, Chemistry


Instruments: B23-Circular Dichroism