Favourable Interfacial Characteristics of A2 Milk Protein Monolayer

Abstract

Shielding of the specific body organ using the biocompatible material helps preventing direct exposure of that part to the foreign entities responsible for infections. Here we show the potential of the A2 milk protein recovered from the milk of cow from Indian origin for possible prevention of the direct exposure to other foreign molecules. We measured the surface pressure of the monolayers of different types of protein samples using Langmuir isotherm experiments. The surface pressure measurements for the monolayer of four types of protein macromolecules have been carried out using the Wilhelmy plate micro pressure sensor. We studied the self-organization of different protein macromolecules and their monolayer compression characteristics. The electrochemical behaviour is studied using electrochemical impedance spectroscopy. We found the highest surface pressure for the monolayer of A2 protein. Further, it is also found that A2 protein exhibited the highest surface activity amongst the other proteins. This property can be effectively used for making the envelope of the A2 protein surrounding the targeted entity.

Keywords: A2 protein; Casein; Competitive interfacial activity; Coronavirus; Gir cow milk; Langmuir monolayer isotherm.

Fig. 1

The schematic diagram for the experimental setup: a surface pressure sensor, b microsyringe, c barrier motor, d Whilhelmy plate

Fig. 2

Surface pressure-area isotherms for A2 protein, casein protein, commercially available casein protein and whey protein

Fig. 3

Electrochemical impedance analysis for protein samples. Equivalent circuit parameters: R₁-solution resistance, R₂-charge resistance, CPE constant phase element, and W Warburg constant

Fig. 4

Surface pressure measurements with respect to time of relaxation for protein samples