Isoenzyme (isozyme)
Definition
Multiple molecular forms of the same enzyme that differ in amino acid sequence but catalyse the same reaction. In forensic serology, isoenzyme patterns in bloodstains can be resolved by gel electrophoresis and compared to reference samples for individualisation. Useful when DNA is too degraded for profiling.
Related terms
- Amino acid
- The monomer unit of proteins. All 20 standard amino acids share a central carbon bonded to an amino group, a carboxyl group,...
- Haemoglobin
- The iron-containing oxygen-transport protein in red blood cells, composed of four polypeptide subunits each with a haem prosthetic group. Its pseudoperoxidase activity...
- Peroxidase
- An enzyme that catalyses the transfer of oxygen from hydrogen peroxide to an electron donor, often producing a coloured product. Haemoglobin has...
- Protein denaturation
- The loss of a protein's three-dimensional structure without breaking peptide bonds, caused by heat, pH change, UV radiation, or chemical agents such...
- Proteolysis
- The hydrolytic cleavage of peptide bonds by proteolytic enzymes (proteases). In biological evidence, proteolysis occurs via endogenous cellular proteases released during autolysis...
Explained in
- Proteins and Enzymes in Biological EvidenceMultiple molecular forms of the same enzyme that differ in amino acid sequence but catalyse the same reaction. In forensic serology, isoenzyme patterns in bloo...