Ultraslow Biological Water-Like Dynamics in Waterless Liquid Protein

J Phys Chem Lett. 2022 May 19;13(19):4389-4393. doi: 10.1021/acs.jpclett.2c00702. Epub 2022 May 12.

Abstract

Fluorescence correlation spectroscopy and time-dependent fluorescence Stokes shift have been employed to elucidate dynamics in different time scales, ranging from picoseconds to nanoseconds, for human serum albumin, in its native and cationized forms as well as in the self-assembled complex of the cationized protein with the polymer surfactant (PS) glycolic acid ethoxylate lauryl ether. The effect of crowding in this complex, especially in the waterless condition, is of prime importance in this context. Excellent correlation of the dynamics with the structures, obtained by circular dichroism and Fourier transform infrared spectroscopy, has been observed. Slow solvation, associated classically with biological water, has been observed in these systems, even in the waterless condition. This apparently intriguing observation has been rationalized by the relaxation of segments of the protein and the PS in the microenvironment of the fluorescent probe.

MeSH terms

  • Circular Dichroism
  • Humans
  • Polymers
  • Proteins*
  • Spectrometry, Fluorescence
  • Surface-Active Agents / chemistry
  • Water*

Substances

  • Polymers
  • Proteins
  • Surface-Active Agents
  • Water