5.REGULATION OF PROTEIN ACTIVITY: Allosteric molecules Conformational change → change in activity Mechanisms of protein activity regulation: Binding of ion/atom: IRP (iron regulatory protein) (Fe) Binding of small molecule : Glycosylation: glycoprotein[FIG.] Phosphorylation: protein kinase, phosphatase[FIG.] Binding of GTP: GTP-binding proteins Binding of protein: cyclin dependent kinase (cyclin) Proteolytic cleavage: insulin, caspases[FIG.] Regulation of enzyme activity: Negative regulation (feedback inhibition)[FIG.] Positive regulation 31