Inhibitors pepsin

Marcus R, Watt J Ulcerative colitis in laboratory animals induced by pepsin inhibitors. Gastroenterology 1974 67 473-483. 

H. Umezawa, T. Aoyagi, H. Morishima, M. Matsuzaki, and M. Hamada, Pepstatin, a new pepsin inhibitor produced by actinomycetes, J. Antibiot. (Tokyo) 23 259 (1970). 

For an intended drug uptake in the stomach, the only proteolytic enzyme which has to be inhibited is pepsin. It has been demonstrated that the polymeric pepsin-inhibitor conjugate chitosan-pepstatin was capable to efficiently protect the peptide drug calcitonin in the presence of pepsin. These results have been additionally confirmed in vivo. The administration of minitablets comprising of a mixture of calcitonin, chitosan, and chitosan-pepstatin to rats led to a reduction of the plasma calcium level, whereas no effect was observed when... 

Fig. 8.4 Decrease in plasma calcium level as a biological response for the salmon calcitonin bioavailability in fasted rats after oral administration of chitosan minitablets ( ), chitosan/ chitosan-pepsin inhibitor conjugate minitablets ( ) and thiolated chitosan/chitosan-pepsin inhibitor conjugate minitablets (A), all containing 50 pg of the peptide drug. Indicated values are the mean results from five rats S.D. (Guggi et al. 2003)...

Anchusa Pepsin inhibitor (63 kDa macromolecule) Anchusa strigosa (Boraginaceae) [root] Pepsin [20 nM] [37]... 

Ascaris pepsin inhibitor 3 aspartic proteases, cathepsin E, pepsin, gastracin Competitive some specificity 1-100 nM (7)... 

The ascaris pepsin inhibitor-3 is an aspin, which is a family of inhibitors of aspartic proteases that protect worms from host gastric enzymes. Like the cystatins, the aspins are competitive inhibitors that bind in the substrate-binding subsites, but they do not have an amide bond that is available for nucleophilic attack. They gain most of their inhibitory activity by inserting their 3 N-terminal residues in the ST-S3 subsites of the protease (6) (Fig. 3). 

Ng KK, et al. Structural basis for die inhibition of porcine pepsin by Ascaris pepsin inhibitor-3. Nat. Struct. Biol. 2000 7 653-657. 

V3. Van Vunakis, H., and Herriott, R., Structural changes associated with the conversion of pepsinogen to pepsin, I. The N-terminal amino acid residue and amino acid composition of the pepsin inhibitor. Biochim. Biophys. Acta 22, 537-543 (1956). 

In subsequent observations S7c), the authors noted that acidification of all 3 pepsinogens to pH 2 for 8 minutes, followed by incubation at various pH s, from 1.1 to 7.2, and then alkalinization at pH 7.8, leads to formation of intermediate compounds between pepsinogens and pepsins. These were designated as pepsin-pepsin-inhibitor complexes (HPPI). These complexes have no milk-clotting activity at pH 5.5 and... 

Pepsin inhibitors Pepsin inhibitors combine with protein to form a viscous, nonabsorbable cover for the ulcers. One example of a pepsin inhibitor is ... 

Pepsin inhibitors combine with protein, forming a viscous, nonabsorbable cover for the ulcers. 

Pepsin inhibitors, sulfated amylopectin (Depepsin),and carrageenin decrease acid secretion in experimental animals and protect animals against histamine-induced ulcers (265). They have to be studied further adequately to ascertain their therapeutic usefulness. 

Martzen, M. R., McMullen, B. A., Smith, N. E., Fujikawa, K. and Peanasky, R. J. (1990) Primary structure of the major pepsin inhibitor from the intestinal parasitic nematode Ascaris suum. Biochemistry 29 7366-7372. 

Pepsin inhibitors such as sucralfate (Carafate) are mucosal protective drags that are non-absorbable and combine with protein to form a viscous substance that covers the ulcer. This protects it from acid and pepsin. Pepsin inhibitors do not neutralize acid or decrease acid secretions. 

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