Isoenzymes can be differentiated from each other by

Identification of Isoenzymes: In Agar gel or polyacrylamide gel electrophoresis, the isoenzymes have different mobility. LDH, CK and ALP isoenzymes can be separated by electrophoresis. Heat stability: One of the isoenzymes may be easily denatured by heat, e.g. bone isoenzyme of ALP (BALP). Inhibitors: One of the isoenzymes may be sensitive to one inhibitor, e.g. tarate labile ACP. Km value or substrate specificity may be different for isoenzymes, e.g. glucokinase has high Km and hexokinase has low Km for glucose. glucokinase specifically acts on glucose as substrate while hexokinase can phosphorylate any hexose sugar. Co-factor requirements may be different for isoenzymes. Mitochondrial isocitrate dehydrogenase is NAD+ dependent and the cytoplasmic isoenzyme is NADP+ dependent Tissue localization may be different for isoenzymes. H4 form of LDH is present in hea, while M4 variety is seen in skeletal muscle. Specific antibodies may identify different types of isoenzymes. For example, CK isoenzymes are separated by antibodies.