Deoxyribonuclease II (, ''
DNase Deoxyribonuclease (DNase, for short) refers to a group of glycoprotein endonucleases which are enzymes that catalyze the hydrolytic cleavage of phosphodiester linkages in the DNA backbone, thus degrading DNA. The role of the DNase enzyme in cells ...
II'', ''pancreatic DNase II'', ''deoxyribonucleate 3'-nucleotidohydrolase'', ''pancreatic DNase II'', ''acid deoxyribonuclease'', ''acid DNase'') is an endonuclease that hydrolyzes phosphodiester linkages of
deoxyribonucleotide
A deoxyribonucleotide is a nucleotide that contains deoxyribose. They are the monomeric units of the informational biopolymer, deoxyribonucleic acid ( DNA). Each deoxyribonucleotide comprises three parts: a deoxyribose sugar (monosaccharide), a ni ...
in native and denatured
DNA, yielding products with 3'-phosphates and 5'-hydroxyl ends, which occurs as a result of single-strand cleaving mechanism.
As the name implies, it functions optimally at
acid
In computer science, ACID ( atomicity, consistency, isolation, durability) is a set of properties of database transactions intended to guarantee data validity despite errors, power failures, and other mishaps. In the context of databases, a sequ ...
pH because it is commonly found in low pH environment of
lysosome
A lysosome () is a membrane-bound organelle found in many animal cells. They are spherical vesicles that contain hydrolytic enzymes that can break down many kinds of biomolecules. A lysosome has a specific composition, of both its membrane prot ...
s.
The action of DNase occurs in three phases. The initial phase introduces multiple nicks in the
phosphodiester backbone. The second phase produces acid-soluble nucleotides. The third phase, which is the terminal phase, consists of
hyperchromic shift resulting from reduction of oligonucleotides.
There are several known
DNase Deoxyribonuclease (DNase, for short) refers to a group of glycoprotein endonucleases which are enzymes that catalyze the hydrolytic cleavage of phosphodiester linkages in the DNA backbone, thus degrading DNA. The role of the DNase enzyme in cells ...
s II, including:
* DNase II alpha (usually known as DNase II), which is thought to be ubiquitously expressed in human tissue. It has been shown that a mutation in this enzyme of mice leads to DNA degradation by apoptosis.
* DNase II beta (also called DLAD, or DNase II-Like Acid DNase), which is mainly expressed in the
eye lens
The lens, or crystalline lens, is a transparent biconvex structure in the eye that, along with the cornea, helps to refract light to be focused on the retina. By changing shape, it functions to change the focal length of the eye so that it can ...
and
salivary glands
The salivary glands in mammals are exocrine glands that produce saliva through a system of ducts. Humans have three paired major salivary glands (parotid, submandibular, and sublingual), as well as hundreds of minor salivary glands. Salivary gla ...
. One of its functions is to clear DNA from eye lens. Low levels have also been detected in the lung, prostate and lymph nodes.
Deficiency of this enzyme in mice lead to the development of cataracts.
References
External links
*
EC 3.1.22
{{3.1-enzyme-stub