Trypsinogens

Fehlhammer, H., Bode, W., Huber, R. Crystal structure of bovine trypsinogen at 1.8 A resolution. 11. Crystallographic refinement, refined crystal structure and comparison with bovine trypsin. J. Mol. Biol. 

Fractionated ammonium sulfate precipitaion of a-chymotrypsinogen (further fractions contain deoxyribonuclease, chymotrypsinogen B, ribonuclease, trypsinogen). 

The proteases are secreted as inactive zymogens the active site of the enzyme is masked by a small region of its peptide chain, which is removed by hydrolysis of a specific peptide bond. Pepsinogen is activated to pepsin by gastric acid and by activated pepsin (autocatalysis). In the small intestine, trypsinogen, the precursor of trypsin, is activated by enteropeptidase, which is secreted by the duodenal epithelial cells trypsin can then activate chymotrypsinogen to chymotrypsin, proelas-tase to elastase, procarboxypeptidase to carboxypepti-dase, and proaminopeptidase to aminopeptidase. 

Figure 6 Separation of basic proteins on an untreated fused silica capillary with diaminopropane as buffer additive. Capillary 75 cm (55 cm to detector) x 50 p i.d. Buffer pHs are as noted on the figure with 30 to 60 mM DAP as an additive 200 to 240 V/cm peak identification 1 = lysozyme, 2 = cytochrome, 3 = ribonuclease, 4 = a-chymotrypsin 5 = trypsinogen, 6 = r-huIL-4. (From Bullock, J. A. and Yuan, L.-C., /. Microcol. Sep., 3, 241, 1991. With permission.)...

Trypsin A proteolytic enzyme formed in the small intestine from trypsinogen. 

S. T. Tzannis and S. J. Prestrelski, Activity-stability considerations of trypsinogen during spray drying Effects of sucrose, J. Pharm. Sci, 88(3), 351 (1999). 

Kenner, R. A. and Aboderin, A. A. (1971). A new fluorescent probe for protein and nucleoprotein conformation. Binding of 7-(p-Methoxyben-zylamino) -4-nitrobenzoxadiazole to bovine trypsinogen and bacterial ribosomes. Biochemistry 10, 4433 1440. 

Vincent, J.P., Lazdunski, M., and Delaage, M. (1970) Use of tetranitromethane as a nitration reagent. Reaction of phenol sidechains in bovine and porcine trypsinogens and trypsins. Eur. ]. Biochem. 12, 250. 

Trypsinogen und Trj psin (vorlaufige Struktur Rind) (lEa/sA und Mit-arbcitcr (109)). 

Huber and associates have refined the structure of trypsinogen in methanol-water, inidally at 213 K (Singh et al., 1980) and subsequently... 

Proteolysis cleavage of peptide bonds to remodel proteins and activate them (ptoin-sulin, trypsinogen, prothrombinj... 

Protein digestion occurs in two stages endopeptidases catalyse the hydrolysis of peptide bonds within the protein molecule to form peptides, and the peptides are hydrolysed to form the amino acids by exopeptidases and dipeptidases. Enteropeptidase initiates pro-enzyme activation in the small intestine by catalysing the conversion of trypsinogen into trypsin. Trypsin is able to achieve further activation of trypsinogen, i.e. an autocatalytic process, and also activates chymotrypsinogen and pro-elastase, by the selective hydro-... 

Trypsinogen plays a key role among the proenzymes released by the pancreas. In the bowel, it is proteolytically converted into active trypsin (see p. 176) by enteropeptidase, a membrane enzyme on the surface of the en-terocytes. Trypsin then autocatalytically activates additional trypsinogen molecules and the other proenzymes (left). 

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