Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Peptidase elastase

This is a 29-kDa protein that has NH 2-terminal sequence homology with elastase and cathepsin G. However, it contains glycine and not serine at the predicted catalytic site, and so lacks protease and peptidase activity. Purified azurocidin kills a range of organisms (e.g. E. coli, S.faecalis, and C. albicans) in vitro. It functions optimally at pH 5.5 and in conditions of low ionic strength. [Pg.71]

Elastase mainly cleaves on the C side of the aliphatic amino acids Gly, Ala, Val, and lie. Smaller peptides are attacked by carboxy-peptidases, which as exopeptidases cleave individual amino acids from the C-terminal end of the peptides (see p. 176). [Pg.268]

Protein degradation is initiated by proteinoses—hy pepsins in the stomach and by trypsin, chymotrypsin, and elastase in the small intestine. The resulting peptides are then further hydrolyzed by various peptidases into amino... [Pg.272]

The major group of enzymes produced by the pancreas and secreted into the duodenum as an aqueous bicarbonate solution is the peptidases. There are three endopeptidases, trypsin, chymotrypsin and elastase, and two exopeptidases,... [Pg.9]

Hydrolysis of peptides and proteins in the GI tract can occur luminally, at the brash border and intracellularly. Luminal activity from the pancreatic proteases trypsin, chymotrypsin, elastase and carboxypeptidase A is mainly directed against large dietary proteins. The main enzymatic activity against small bioactive peptides is derived from the bmsh border of the enterocyte. Brash border proteases, such as aminopeptidase A and N, diaminopeptidease IV and Zn-stable Asp-Lys peptidase, preferentially cleave oligopeptides of up to 10 ammo acid residues and are particularly effective in the cleavage of tri- and tetra-peptides. [Pg.35]

Luminal and Membrane Metabolism of Peptides and Proteins. In meaningful studies on peptide and protein drug absorption in the small intestine, it is prerequisite to distinguish among cavital, membrane contact, and intracellular drug metabolism.Cavital metabolism takes place in the lumen of the small intestine by enzymes such as trypsin, chymotrypsin, carboxypepti-dase, and elastase, which are secreted by the pancreas. Membrane contact metabolism is carried out by aminopeptidases lo-calized on the brush border membrane. Intracellular metabolism occurs inside of the cells. The known intra-celluar enzymes are cytoplasmic peptidases, prolidase, dipeptidase, and tripeptidase.A more detailed dis-cussion of this topic is presented in section Intestinal Absorption Barriers, later. [Pg.2716]

Much but not all of this work has dealt with proteins the three-dimensional structures of which have been determined by x ray lysozyme, ribonuclease, myoglobin, hemoglobin, cytochrome C, carboxy-peptidase, chymotrypsin, concanavalin, trypsin, elastase, and sub-tilisin. The principal nucleus has been the proton, but more recently 13 C has been studied by several groups. Other nuclei, such as 19 F, 31P, and 35Cl, have found limited application in special studies. [Pg.249]

Excretions/secretions enzymatically degrade only the necrotic tissue by the action of various proteol3ftic enzymes such as peptidases, collagenases, and elastases (Vistnes et al., 1981). [Pg.83]

Proteins can be modified by a group of peptide hydrolyses (peptidases) commonly called proteases (or proteinoses). Based on their ability to hydrolyze specific proteins, proteases are classified as collagenase, keratinase, elastase, etc. On the basis of the pH range over which they are active, they are classified as either acidic, neutral, or alkaline. However, according to their mechanism of action, the Enzyme Commission classifies proteases into the four distinct classes of serine, cysteine, aspartyl, and metalloproteases. Serine proteases, for example, always contain serine residue at their catalytic center, which is essential for the action of proteolysis. [Pg.24]

Fig. 3.15. Variations and character of accessible surface area as a result of formation of secondary structures in six proteins pancreatic trypsin inhibitor (PTI), calcium binding protein (CBP), Bence-Jones protein REI (VIM), elastase (ELA), thermolysin (TLS), and carboxy-peptidase A (CPA). (A) Surface which remains accessible (B) surface which becomes buried. The partition, polar, charged, and nonpolar surface is indicated in all cases (according to Chothia, 1976). Fig. 3.15. Variations and character of accessible surface area as a result of formation of secondary structures in six proteins pancreatic trypsin inhibitor (PTI), calcium binding protein (CBP), Bence-Jones protein REI (VIM), elastase (ELA), thermolysin (TLS), and carboxy-peptidase A (CPA). (A) Surface which remains accessible (B) surface which becomes buried. The partition, polar, charged, and nonpolar surface is indicated in all cases (according to Chothia, 1976).

See other pages where Peptidase elastase is mentioned: [Pg.12]    [Pg.5]    [Pg.12]    [Pg.5]    [Pg.96]    [Pg.159]    [Pg.171]    [Pg.361]    [Pg.125]    [Pg.268]    [Pg.357]    [Pg.178]    [Pg.246]    [Pg.351]    [Pg.357]    [Pg.93]    [Pg.408]    [Pg.226]    [Pg.768]    [Pg.10]    [Pg.248]    [Pg.229]    [Pg.1708]    [Pg.2057]    [Pg.59]    [Pg.1855]    [Pg.813]    [Pg.816]    [Pg.81]    [Pg.101]    [Pg.305]    [Pg.103]    [Pg.251]    [Pg.694]    [Pg.229]   
See also in sourсe #XX -- [ Pg.76 , Pg.314 , Pg.357 ]




SEARCH



Elastase

Peptidases

© 2024 chempedia.info