Mechanosensing in plants is thought to be governed by sensory complexes containing a Ca2+-permeable, mechanosensitive channel. The plasma membrane protein MCA1 and its paralog MCA2 from Arabidopsis thaliana are involved in mechanical stress-induced Ca2+ influx and are thus considered as candidates for such channels or their regulators. Both MCA1 and MCA2 were functionally expressed in Sf9 cells using a baculovirus system in order to elucidate their molecular natures. Because of the abundance of protein in these cells, MCA2 was chosen for purification. Purified MCA2 in a detergent-solubilized state formed a tetramer, which was confirmed by chemical cross-linking. Single-particle analysis of cryo-electron microscope images was performed to depict the overall shape of the purified protein. The three-dimensional structure of MCA2 was reconstructed at a resolution of 26 Å from 5,500 particles and appears to comprise a small transmembrane region and large cytoplasmic region.

Denaturation of protein is a biological phenomenon in which a protein loses its native shape due to the breaking or disruption of weak chemical bonds and interactions which makes the protein biologically inactive. It is the process where properly folded proteins formed under physiological conditions is transformed to an unfolded protein under non-physiological conditions. The process of denaturation of proteins can occur under different physiological and chemical conditions. Denaturation can be reversible or irreversible. Denaturation mostly takes places when the protein is subjected under external elements like inorganic solutes, organic solvents, acids or bases, and by heat or irradiations. The denaturing agents or denaturants widely used in protein folding or unfolding experiments are urea and guanidinium chloride (GdmCl). In denaturation, the alpha-helix structure and beta sheets structure of the native protein are disrupted and unfolds it into any random shape. We can also say that denaturation occurs due to the disruption of bonding interactions which are responsible for secondary structure and the tertiary structure of the proteins.

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