ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Interaction of ectoine and hydroxyectoine with protein: fluorescence study

Auguste Rasteniene, Ruta Gruskiene, and Jolanta Sereikaite

Department of Chemistry and Bioengineering, Faculty of Fundamental Sciences, Vilnius Gediminas Technical University, Vilnius-40, Lithuania

E-mail: jolanta.sereikaite@vgtu.lt

Received: 12 November 2020  Accepted: 19 January 2021

Abstract:

Ectoine and hydroxyectoine are well known extremolytes that accumulate in halophilic and halotolerant microorganisms. They are investigated as protein stabilizers and as excipients in protein formulations and biopharmaceuticals. However, their effect is quite controversial. In this work, the influence of both extremolytes on mink growth hormone as a model protein was studied by fluorescence spectroscopy. The study revealed that the fluorescence quenching of protein tryptophan by ectoine and hydroxyectoine differs and is dependent on the pH value of solution. Moreover, the quenching mode by ectoine and hydroxyectoine was compared with a well-known quencher acrylamide. The differences in the extremolytes interaction with protein revealed by fluorescence spectroscopy could be related to their different effect as protein stabilizers under various conditions.

Keywords: Ectoine; Hydroxyectoine; Mink growth hormone; Acrylamide; Fluorescence quenching; Sphere action static mechanism

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-021-01527-9

Chemical Papers 75 (6) 2703–2712 (2021)