DNAse

DNase refers to a group of enzymes known as deoxyribonucleases that hydrolyze DNA by cleaving phosphodiester bonds. The most studied forms are DNase I and DNase II. DNase I is a calcium- and magnesium-dependent enzyme that operates mainly outside cells and in biological fluids, whereas DNase II is an acid hydrolase located in lysosomes and active at low pH, where it degrades DNA within phagolysosomes.

Biochemical properties and mechanism vary by type. DNase I acts on double- and single-stranded DNA and requires divalent cations (Ca2+ and Mg2+) for activity; it can be inhibited by certain proteins such as actin. DNase II functions in acidic intracellular compartments and does not require divalent cations. Both enzymes cleave DNA to produce smaller DNA fragments, contributing to DNA turnover and the processing of intracellular and extracellular DNA.

Physiological and pathological roles include participation in apoptosis and cellular turnover, degradation of DNA contained in neutrophil extracellular traps, and clearance of extracellular DNA to prevent improper immune activation. DNase activity helps remodel DNA during development and immunity and is important for maintaining genomic and extracellular DNA balance.

Applications and clinical relevance span laboratory and medical uses. In laboratories, DNase I is routinely used to remove DNA contamination from RNA preparations and to prevent DNA-mediated artifacts in experiments. In medicine, recombinant human DNase I (dornase alfa) is used as an inhaled therapy for cystic fibrosis to reduce mucus viscosity by digesting extracellular DNA from neutrophils. DNase inhibitors, buffers, and inactivation steps are commonly employed to control activity in experiments.

Common sources include bovine, porcine, and microbial preparations for research, with recombinant forms widely used in clinical and diagnostic settings. Safety and handling depend on the specific preparation and application.