What is the significance of isoionic point in the context of protein structure and function?

The isoionic point, also known as the isoelectric point, is the pH at which a protein has no net charge. This is significant in protein structure and function because it affects the protein's solubility, stability, and interactions with other molecules. At the isoionic point, a protein is least soluble and may undergo conformational changes that impact its function.