Activation of pancreatic zymogens

Rinderknecht, H.

doi:10.1007/bf01318124

Cited by 285 publications

(76 citation statements)

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“…Duodenase exhibits a marked preference for specific proteins and artificial substrates, indicating that it is a regulatory enzyme with a functional role in the duodenum rather than a digestive protease. The classical example of such a regulating process in the duodenum is the activation cascade of pancreatic enzymes [ 2 ] . In the first stage of this cascade active trypsin is generated from its zymogen by enteropeptidase, and in the second stage trypsin activates the remaining pancreatic zymogens.…”

Section: Resultsmentioning

confidence: 99%

Subcellular Localization, Substrate Specificity and Crystallization of Duodenase, A Potential Activator of Enteropeptidase

Замолодчикова¹,

Sokolova²,

Alexandrov³

et al. 1997

European Journal of Biochemistry

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Duodenase, a serine protease from bovine duodenum mucosa, was located in endoplasmic reticulum, the Golgi secretory granules of epithelial cells and ducts of Brunner's glands by the A-gold iinmunocytochemical method. Duodenase exhibits trypsin-like and chyinotrypsin-like specificities with a preference for substrates having lysine at the P1 and proline at the P2 positions. The kinetic constants for the hydrolysis of 21 potential duodenase substrates are reported. The best substrates were found to be a-N-tosylglycylprolyllysine 4-nitroanilide (kJK,,, of 35 000 M-' s-'), a-N-succinylthreonylprolyllysine 4-nitroanilide (kc4,/K1,! of 18 000 M-' s-') and a-N-serylprolyllysine 4-nitroanilide (k,JK,, of 2600 M-' s-I), all of which contain the P I -P3 sequence of the enteropeptidase zymogen/activation site. On the basis of its catalytic properties and sites of localization, duodenase has been postulated to be an activator of the enteropeptidase precursor. A tetradecapeptide (LVTQEVSPKIVGGS) having the P9 -PS'sequence of the cleavage site of zymogen activation of bovine proenteropeptidase was synthesized, and kinetic parameters of its hydrolysis by duodenase were determined (K,,, of 87 pM; k,;,, of 1.4 s-I; k,,,/K,,, of 16000 M-' s-I). Crystals of duodenase frozen in a stream of liquid nitrogen diffracted synchrotron Xrays to 0.2-nm resolution.

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Section: Resultsmentioning

confidence: 99%

Subcellular Localization, Substrate Specificity and Crystallization of Duodenase, A Potential Activator of Enteropeptidase

Замолодчикова¹,

Sokolova²,

Alexandrov³

et al. 1997

European Journal of Biochemistry

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“…Rinderknecht was also the first to identify the inhibitor-resistant human mesotrypsin in 1984 (4). He initially alleged that mesotrypsin can degrade trypsinogens, but later he withdrew this conclusion and attributed the trypsinogen-degrading activity to an unidentified serine protease, which he named enzyme Y (7,8). This enigmatic activity developed when human cationic trypsinogen, purified by native gel electrophoresis, was incubated at 37°C.…”

Section: Discussionmentioning

confidence: 99%

“…6 and references therein). Inactivation of intrapancreatic trypsin through trypsin-mediated trypsin degradation (autolysis) or by an unidentified serine protease (enzyme Y) was therefore proposed to be protective against pancreatitis (7)(8)(9)(10)(11). This notion received support from the discovery that the R122H mutation, which eliminates the Arg 122 autolytic site in cationic trypsinogen, causes autosomal dominant hereditary pancreatitis in humans (9).…”

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confidence: 99%

Chymotrypsin C (caldecrin) promotes degradation of human cationic trypsin: Identity with Rinderknecht's enzyme Y

Szmola

Sahin–Tóth

2007

Proc. Natl. Acad. Sci. U.S.A.

148

141

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Digestive trypsins undergo proteolytic breakdown during their transit in the human alimentary tract, which has been assumed to occur through trypsin-mediated cleavages, termed autolysis. Autolysis was also postulated to play a protective role against pancreatitis by eliminating prematurely activated intrapancreatic trypsin. However, autolysis of human cationic trypsin is very slow in vitro, which is inconsistent with the documented intestinal trypsin degradation or a putative protective role. Here we report that degradation of human cationic trypsin is triggered by chymotrypsin C, which selectively cleaves the Leu 81 -Glu 82 peptide bond within the Ca 2؉ binding loop. Further degradation and inactivation of cationic trypsin is then achieved through tryptic cleavage of the Arg 122 -Val 123 peptide bond. Consequently, mutation of either Leu 81 or Arg 122 blocks chymotrypsin C-mediated trypsin degradation. Calcium affords protection against chymotrypsin C-mediated cleavage, with complete stabilization observed at 1 mM concentration. Chymotrypsin C is highly specific in promoting trypsin degradation, because chymotrypsin B1, chymotrypsin B2, elastase 2A, elastase 3A, or elastase 3B are ineffective. Chymotrypsin C also rapidly degrades all three human trypsinogen isoforms and appears identical to enzyme Y, the enigmatic trypsinogen-degrading activity described by Heinrich Rinderknecht in 1988. Taken together with previous observations, the results identify chymotrypsin C as a key regulator of activation and degradation of cationic trypsin. Thus, in the high Ca 2؉ environment of the duodenum, chymotrypsin C facilitates trypsinogen activation, whereas in the lower intestines, chymotrypsin C promotes trypsin degradation as a function of decreasing luminal Ca 2؉ concentrations. chronic pancreatitis ͉ digestive enzymes ͉ trypsinogen degradation

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“…Mesotrypsin, a human trypsin encoded by the PRSS3 gene, is produced and secreted as a digestive zymogen by the pancreas (29); a major splice isoform of mesotrypsinogen termed "trypsinogen 4" and lacking a classical secretion signal is highly expressed in brain tissue (30,31) and in some epithelial cell lines and tumors (32)(33)(34)(35)(36)(37). The splice isoforms differ only at the N terminus, and processing of either form by removal of the prodomain results in active mesotrypsin of identical amino acid sequence (38).…”

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confidence: 99%

Determinants of Affinity and Proteolytic Stability in Interactions of Kunitz Family Protease Inhibitors with Mesotrypsin

Salameh

Soares

Navaneetham

et al. 2010

Journal of Biological Chemistry

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An important functional property of protein protease inhibitors is their stability to proteolysis. Mesotrypsin is a human trypsin that has been implicated in the proteolytic inactivation of several protein protease inhibitors. We have found that bovine pancreatic trypsin inhibitor (BPTI), a Kunitz protease inhibitor, inhibits mesotrypsin very weakly and is slowly proteolyzed, whereas, despite close sequence and structural homology, the Kunitz protease inhibitor domain of the amyloid precursor protein (APPI) binds to mesotrypsin 100 times more tightly and is cleaved 300 times more rapidly. To define features responsible for these differences, we have assessed the binding and cleavage by mesotrypsin of APPI and BPTI reciprocally mutated at two nonidentical residues that make direct contact with the enzyme. We find that Arg at P 1 (versus Lys) favors both tighter binding and more rapid cleavage, whereas Met (versus Arg) at P 2 favors tighter binding but has minimal effect on cleavage. Surprisingly, we find that the APPI scaffold greatly enhances proteolytic cleavage rates, independently of the binding loop. We draw thermodynamic additivity cycles analyzing the interdependence of P 1 and P 2 substitutions and scaffold differences, finding multiple instances in which the contributions of these features are nonadditive. We also report the crystal structure of the mesotrypsin⅐APPI complex, in which we find that the binding loop of APPI displays evidence of increased mobility compared with BPTI. Our data suggest that the enhanced vulnerability of APPI to mesotrypsin cleavage may derive from sequence differences in the scaffold that propagate increased flexibility and mobility to the binding loop.

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Activation of pancreatic zymogens

Cited by 285 publications

References 23 publications

Subcellular Localization, Substrate Specificity and Crystallization of Duodenase, A Potential Activator of Enteropeptidase

Subcellular Localization, Substrate Specificity and Crystallization of Duodenase, A Potential Activator of Enteropeptidase

Chymotrypsin C (caldecrin) promotes degradation of human cationic trypsin: Identity with Rinderknecht's enzyme Y

Determinants of Affinity and Proteolytic Stability in Interactions of Kunitz Family Protease Inhibitors with Mesotrypsin

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