Clostripain (, ''clostridiopeptidase B'', ''clostridium histolyticum proteinase B'', ''alpha-clostridipain'', ''clostridiopeptidase'', ''Endoproteinase Arg-C'') is a
proteinase
A protease (also called a peptidase, proteinase, or proteolytic enzyme) is an enzyme that catalyzes proteolysis, breaking down proteins into smaller polypeptides or single amino acids, and spurring the formation of new protein products. They do ...
that cleaves
protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metab ...
s on the carboxyl peptide bond of
arginine
Arginine is the amino acid with the formula (H2N)(HN)CN(H)(CH2)3CH(NH2)CO2H. The molecule features a guanidinium, guanidino group appended to a standard amino acid framework. At physiological pH, the carboxylic acid is deprotonated (−CO2−) a ...
. It was isolated from ''
Clostridium histolyticum
''Hathewaya histolytica'' (formerly ''Clostridium histolyticum'') is a species of bacteria found in feces and the soil. It is a motile, gram-positive, aerotolerant anaerobe. ''H. histolytica'' is pathogenic in many species, including guinea pigs ...
''. The
isoelectric point
The isoelectric point (pI, pH(I), IEP), is the pH at which a molecule carries no net electric charge, electrical charge or is electrically neutral in the statistical mean. The standard nomenclature to represent the isoelectric point is pH(I). Howe ...
of the
enzyme
An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different mol ...
is 4.8-4.9 (at 8 °C), and optimum pH is 7.4~7.8 (against α-benzoyl-arginine ethyl ester). The composition of the enzyme is indicated to be of two chains of relative
molecular mass
The molecular mass () is the mass of a given molecule, often expressed in units of daltons (Da). Different molecules of the same compound may have different molecular masses because they contain different isotopes of an element. The derived quan ...
45,000 and 12,500.
See also
*
Benzoyl
In organic chemistry, benzoyl (, ) is the functional group with the formula and structure . It can be viewed as benzaldehyde missing one hydrogen. The benzoyl group has a mass of 105 amu.
The term "benzoyl" should not be confused with benzyl ...
*
Ethyl ester
In chemistry, an ester is a compound derived from an acid (either organic or inorganic) in which the hydrogen atom (H) of at least one acidic hydroxyl group () of that acid is replaced by an organyl group (R). These compounds contain a distinct ...
References
External links
*
*
EC 3.4.22
Post-translational modification
{{hydrolase-stub