Hemoglobin Dynamics in Solution vis-à-vis under Confinement: An Electrochemical Perspective

Samajdar, RN and Asampille, G and Atreya, HS and Bhattacharyya, AJ (2020) Hemoglobin Dynamics in Solution vis-à-vis under Confinement: An Electrochemical Perspective. In: Journal of Physical Chemistry B, 124 (28). pp. 5771-5779.

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Abstract

Confining heme protein in silico often leads to beneficial functionalities such as an enhanced electrochemical response from the heme center. This can be harnessed to design effective biosensors for medical diagnostics. Proteins under confinement, surface confinement on the electrode to be precise, have more ordered and monodisperse structure compared to the protein in bulk solution. As the electrochemical response of a protein comes from those protein molecules that are confined within the electrical double layer across the electrode-electrolyte interface, it is expected that restriction of conformational fluctuations of the polymeric protein will help in enhancement of the electrochemical response. This is probably the prima facie reason for electrochemical response enhancement under confinement. We examine the dynamic features of hemoglobin under confinement vis-à -vis that in bulk solution. We use a variety of spectroscopic techniques across a wide time-space window to establish the following facts: (a) hardening of the protein polypeptide backbone, (b) slowing down of protein diffusion, (c) increase in relaxation times in NMR, and (d) slowing down of dielectric relaxation times under confinement. This indicates an overall quenching of protein dynamics when the protein is confined inside silica matrix. Thus, we hypothesize that along with retention of secondary structure, this quenching of dynamics contributes to the enhancement of electrochemical response observed. Copyright © 2020 American Chemical Society.

Item Type:	Journal Article
Publication:	Journal of Physical Chemistry B
Publisher:	American Chemical Society
Additional Information:	The copyright for this article belongs to American Chemical Society.
Keywords:	Diagnosis; Dielectric relaxation; Dynamics; Electrochemical electrodes; Electrolytes; Hemoglobin; Porphyrins; Quenching; Relaxation time; Silica, Conformational fluctuations; Electrical double layers; Electrochemical response; Electrode-electrolyte interfaces; Monodisperse structures; Polypeptide backbones; Secondary structures; Spectroscopic technique, Proteins, hemoglobin; polymer; silicon dioxide, diffusion; protein secondary structure, Diffusion; Hemoglobins; Polymers; Protein Structure, Secondary; Silicon Dioxide
Department/Centre:	Division of Chemical Sciences > NMR Research Centre (Formerly Sophisticated Instruments Facility) Division of Chemical Sciences > Solid State & Structural Chemistry Unit
Date Deposited:	03 Feb 2023 05:04
Last Modified:	03 Feb 2023 05:04
URI:	https://eprints.iisc.ac.in/id/eprint/79823

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