The influence of Li+ ions on pepsin and trypsin activity in vitro

2021 ◽  
Vol 66 ◽  
pp. 126763
Author(s):  
Karolina Kabzińska ◽  
Angelika Cisek-Woźniak ◽  
Dominik Czajeczny ◽  
Kinga Mruczyk ◽  
Rafał W. Wójciak
Keyword(s):  
Trypsin Activity

scholarly journals SPINK1-induced amelioration of impaired autophagy contributes to suppression of trypsinogen activation in a model of acute pancreatitis

2020 ◽  
Author(s):  
Yuxiao Zhao ◽  
Jianlong Jia ◽  
Abdullah Shopit ◽  
Yang Liu ◽  
Jun Wang
Keyword(s):  
Acute Pancreatitis ◽  
In Vitro Model ◽  
Autophagic Flux ◽  
Trypsin Activity ◽  
Autophagy Flux ◽  
Trypsinogen Activation ◽  
Vitro Model ◽  
First Time ◽  
Induced Amelioration

AbstractSPINK1 has been regarded as a reversible trypsinogen inhibitor for the inappropriate activation of trypsin, a key step in the initiation of acute pancreatitis (AP). However, the mechanisms of its action remains largely unclear and controversial. Here, we reported an unexpected effects of SPINK1 on inhibiting trypsinogen activation through the regulation of impaired autophagy in cerulein-stimulated AR42J cells, a well-established in vitro model of acute pancreatitis. Firstly, we found that the impaired autophagic flux was induced and trypsinogen activity enhanced in the above setting. Then, we showed that SPINK1 overexpression could inhibit the level of increased autophagic activity, improving the hindered autophagy flux, and significantly decreased the trypsinogen activity, whereas shRNA-caused downregulation of SPINK1 exacerbated the impairment of autophagic flux and trypsin activity, in the same cerulein-processed cells. More importantly, the trypsinogen activation in this model could be ameliorated by 3-Methyladenine(3-MA), an autophagy inhibitor. Thus, this study revealed, possibly for the first time, that SPINK1 greatly blocked the trypsinogen activation possibly through the modulation of impaired autophagy in cerulein-induced in vitro model of acute pancreatitis.

Intra-acinar cell activation of trypsinogen during caerulein-induced pancreatitis in rats

1998 ◽  
Vol 275 (2) ◽  
pp. G352-G362 ◽  
Author(s):  
B. Hofbauer ◽  
A. K. Saluja ◽  
M. M. Lerch ◽  
L. Bhagat ◽  
M. Bhatia ◽  
...  
Keyword(s):  
Cell Activation ◽  
Digestive Enzyme ◽  
Light And Electron Microscopy ◽  
Subcellular Fractionation ◽  
Trypsin Activity ◽  
Lysosomal Hydrolases ◽  
Pancreatic Acini ◽  
Trypsinogen Activation ◽  
Supramaximal Stimulation

Supramaximal stimulation of the pancreas with the CCK analog caerulein causes acute edematous pancreatitis. In this model, active trypsin can be detected in the pancreas shortly after the start of supramaximal stimulation. Incubation of pancreatic acini in vitro with a supramaximally stimulating caerulein concentration also results in rapid activation of trypsinogen. In the current study, we have used the techniques of subcellular fractionation and both light and electron microscopy immunolocalization to identify the site of trypsinogen activation and the subsequent fate of trypsin during caerulein-induced pancreatitis. We report that trypsin activity and trypsinogen-activation peptide (TAP), which is released on activation of trypsinogen, are first detectable in a heavy subcellular fraction. This fraction is enriched in digestive enzyme zymogens and lysosomal hydrolases. Subsequent to trypsinogen activation, both trypsin activity and TAP move to a soluble compartment. Immunolocalization studies indicate that trypsinogen activation occurs in cytoplasmic vacuoles that contain the lysosomal hydrolase cathepsin B. These observations suggest that, during the early stages of pancreatitis, trypsinogen is activated in subcellular organelles containing colocalized digestive enzyme zymogens and lysosomal hydrolases and that, subsequent to its activation, trypsin is released into the cytosol.

scholarly journals Resistance to Aspergillus flavus in Corn Kernels Is Associated with a 14-kDa Protein

1998 ◽  
Vol 88 (4) ◽  
pp. 276-281 ◽  
Author(s):  
Z.-Y. Chen ◽  
R. L. Brown ◽  
A. R. Lax ◽  
B. Z. Guo ◽  
T. E. Cleveland ◽  
...  
Keyword(s):  
Aspergillus Flavus ◽  
Trypsin Inhibitor ◽  
Aflatoxin Contamination ◽  
Inhibitor Protein ◽  
Trypsin Activity ◽  
Terminal Sequence ◽  
High Concentration ◽  
Resistant Varieties ◽  
Corn Kernels

Corn genotypes resistant or susceptible to Aspergillus flavus were extracted for protein analysis using a pH 2.8 buffer. The profile of protein extracts revealed that a 14-kDa protein is present in relatively high concentration in kernels of seven resistant corn genotypes, but is absent or present only in low concentration in kernels of six susceptible ones. The N-terminal sequence of this 14-kDa protein showed 100% homology to a corn trypsin inhibitor. The 14-kDa protein purified from resistant varieties also demonstrated in vitro inhibition of both trypsin activity and the growth of A. flavus. This is the first demonstration of antifungal activity of a corn 14-kDa trypsin inhibitor protein. The expression of this protein among tested genotypes may be related to their difference in resistance to A. flavus infection and subsequent aflatoxin contamination.

scholarly journals Rational Design of a Novel Propeptide for Improving Active Production of Streptomyces griseus Trypsin in Pichia pastoris

2013 ◽  
Vol 79 (12) ◽  
pp. 3851-3855 ◽  
Author(s):  
Zhenmin Ling ◽  
Yi Liu ◽  
Shaolei Teng ◽  
Zhen Kang ◽  
Jingjing Zhang ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Amino Acid ◽  
Pichia Pastoris ◽  
In Silico ◽  
Rational Design ◽  
Streptomyces Griseus ◽  
Trypsin Activity ◽  
Content Type ◽  
Profound Influence

ABSTRACTApplyingin silicosimulations andin vitroexperiments, the amino acid proline was proved to have a profound influence onStreptomyces griseustrypsinogen, and the hydrogen bond between H57and D102was found to be crucial for trypsin activity. By introducing an artificial propeptide, IVEF, the titer of trypsin was increased 6.71-fold.

Inhibition of trypsin activity in vitro by phytate

1982 ◽  
Vol 30 (4) ◽  
pp. 799-800 ◽  
Author(s):  
Madhav Singh ◽  
A. D. Krikorian
Keyword(s):  
Trypsin Activity

scholarly journals In Vitro Assessment of the Impact of Industrial Processes on the Gastrointestinal Digestion of Milk Protein Matrices Using the INFOGEST Protocol

Foods ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1580
Author(s):  
Nathalie Atallah ◽  
Barbara Deracinois ◽  
Audrey Boulier ◽  
Alain Baniel ◽  
Delphine Jouan-Rimbaud Bouveresse ◽  
...  
Keyword(s):  
Milk Protein ◽  
Protein Structures ◽  
Sodium Dodecyl ◽  
Size Exclusion ◽  
Industrial Processes ◽  
Protein Distribution ◽  
Trypsin Activity ◽  
Protein Matrices ◽  
The Impact

The goal of this study was to determine the impact of industrial processes on the digestion of six milk protein matrices using the harmonized INFOGEST in vitro static digestion protocol. First, this method was optimized to simple protein matrices using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and size exclusion chromatography (SEC) to compare the intestinal protein hydrolysis obtained with increasing quantities of pancreatin. Similar results were achieved with the originally required pancreatin amount (trypsin activity of 100 U.mL−1) and with a quantity of pancreatin equivalent to a trypsin activity of 27.3 U.mL−1, which was thus used to perform the in vitro digestion of the milk matrices. Molecular weight profiles, peptide heterogeneity from LC-MS/MS data, calcium, free amino acid, and peptide concentrations were determined in the gastric and intestinal phases to compare the milk protein digests. Results showed that the industrial process affected not only the protein distribution of the matrices but also most likely the protein structures. Indeed, differences arose in terms of peptide populations generated when the caseins were reticulated or when their calcium concentrations were reduced.

Isolation of the first trypsin inhibitor from the genus Aspergillus

1985 ◽  
Vol 5 (8) ◽  
pp. 697-700 ◽  
Author(s):  
Rashda Ali ◽  
Zafar H. Zaidi
Keyword(s):  
Trypsin Inhibitor ◽  
Trypsin Activity ◽  
High Concentration ◽  
Intracellular Metabolites ◽  
Aspergillus Flavipes ◽  
Pure Protein ◽  
Sucrose Medium

The fungus Aspergillus flavipes was grown on a Czapeck sucrose medium; the biomass so obtained was treated with high concentration of sucrose to release intracellular metabolites. Sephadex G-75 chromatography of the latter yielded a pure protein having anti-trypsin activity in vitro.

Behaviour of the vitelline envelope in Bufo arenarum oocytes matured in vitro in blockade to polyspermy

Zygote ◽  
2006 ◽  
Vol 14 (2) ◽  
pp. 97-106 ◽  
Author(s):  
J. Oterino ◽  
G. Sánchez Toranzo ◽  
L. Zelarayán ◽  
M.T. Ajmat ◽  
F. Bonilla ◽  
...  
Keyword(s):  
Ultrastructural Changes ◽  
Cortical Granule ◽  
Trypsin Activity ◽  
Trypsin Treatment ◽  
Granule Exocytosis ◽  
Sperm Entry ◽  
Bufo Arenarum ◽  
Vitelline Envelope ◽  
Cortical Granule Exocytosis

SummaryDuring activation of amphibian eggs, cortical granule exocytosis causes elaborate ultrastructural changes in the vitelline envelope. These changes involve modifications in the structure of the vitelline envelope and formation of a fertilization envelope (FE) that can no longer be penetrated by sperm. In Bufo arenarum, as the egg traverses the oviduct, the vitelline envelope is altered by a trypsin-like protease secreted by the oviduct, which induces an increased susceptibility of the vitelline envelope to sperm lysins. Full-grown oocytes of B. arenarum, matured in vitro by progesterone, are polyspermic, although cortical granule exocytosis seems to occur within a normal chronological sequence. These oocytes can be fertilized with or without trypsin treatment, suggesting that the vitelline envelope is totally sperm-permeable. Vitelline envelopes without trypsin treatment cannot retain either gp90 or gp96. This suggests that these glycoproteins are involved in the block to polyspermy and that trypsin treatment of matured in vitro oocytes before insemination is necessary to enable vitelline envelopes to block polyspermy. The loss of the binding capacity in vitelline envelopes isolated from B. arenarum oocytes matured in vitro with trypsin treatment and activated by electric shock suggests that previous trypsin treatment is a necessary step for sperm block to occur. When in vitro matured oocytes were incubated with the product of cortical granules obtained from in vitro matured oocytes (vCGP), vitelline envelopes with trypsin treatment were able to block sperm entry. These oocytes exhibited the characteristic signs of activation. These results support the idea that B. arenarum oocytes can be activated by external stimuli and suggest the presence of unknown oocyte surface receptors linked to the activation machinery in response to fertilization. Electrophoretic profiles obtained by SDS-PAGE of solubilized vitelline envelopes from oocytes matured in vitro revealed the conversion of gp40 (in vitro matured oocytes, without trypsin treatment) to gp38 (ascribable to trypsin activity or cortical granule product activity, CGP) and the conversion of gp70 to gp68 (ascribable to trypsin activity plus CGP activity). Taking into account that only the vitelline envelopes of in vitro matured oocytes with trypsin treatment and activated can block sperm entry, we may suggest that the conversion of gp70 to gp68 is related to the changes associated with sperm binding.

Proteins but not amino acids, carbohydrates, or fats stimulate cholecystokinin secretion in the rat

1986 ◽  
Vol 251 (2) ◽  
pp. G243-G248 ◽  
Author(s):  
R. A. Liddle ◽  
G. M. Green ◽  
C. K. Conrad ◽  
J. A. Williams
Keyword(s):  
Amino Acids ◽  
Bovine Serum Albumin ◽  
Trypsin Inhibitor ◽  
Simultaneous Administration ◽  
Trypsin Activity ◽  
Intact Proteins ◽  
Plasma Cholecystokinin ◽  
Inhibit Trypsin Activity ◽  
Cck Release

Because of prior difficulties in measuring plasma cholecystokinin (CCK) levels, it has not been established which components of food stimulate CCK secretion in rats. In the present study, we used a sensitive and specific bioassay for measuring plasma CCK and determined the effects of proteins, protein hydrolysates, amino acids, fats, starch, and glucose on CCK secretion in this species. Intact proteins were the only stimulants of CCK release. Solutions of 18% casein and 0.2% soybean trypsin inhibitor caused prompt increases in plasma CCK levels from 0.5 +/- 0.2 to 7.9 +/- 1.9 and 8.0 +/- 2.0 pM, respectively, within 5 min of orogastric administration. The proteins lactalbumin and bovine serum albumin caused smaller elevations in circulating CCK. In contrast, hydrolysates of casein and lactalbumin and the amino acids L-phenylalanine and L-tryptophan did not stimulate CCK release. In addition, plasma CCK levels did not increase with the feeding of fat, starch, or glucose. The ability of proteins to stimulate CCK secretion paralleled their ability to inhibit trypsin activity in vitro. Furthermore, the plasma CCK response to casein was completely abolished by the simultaneous administration of trypsin. These studies indicate that proteins are the major food stimulants of CCK release in the rat and that the effects of proteins are related to inhibition of intraluminal protease activity.

Endothelial nitric oxide synthase is protective in the initiation of caerulein-induced acute pancreatitis in mice

2004 ◽  
Vol 287 (1) ◽  
pp. G80-G87 ◽  
Author(s):  
Matthew J. DiMagno ◽  
John A. Williams ◽  
Yibai Hao ◽  
Stephen A. Ernst ◽  
Chung Owyang
Keyword(s):  
Nitric Oxide ◽  
Acute Pancreatitis ◽  
Cell Types ◽  
Microvascular Blood Flow ◽  
Trypsin Activity ◽  
Serum Lipase ◽  
Initiation Phase ◽  
Nos Isoforms

The effect of inhibiting nitric oxide (NO) synthase (NOS) or enhancing NO on the course of acute pancreatitis (AP) is controversial, in part because three NOS isoforms exist: neuronal (nNOS), endothelial (eNOS), and inducible (iNOS). We investigated whether inhibition or selective gene deletion of NOS isoforms modified the initiation phase of caerulein-induced AP in mice and explored whether this affected pancreatic microvascular blood flow (PMBF). We investigated the effects of nonspecific NOS inhibition with Nω-nitro-l-arginine (l-NNA; 10 mg/kg ip) or targeted deletion of eNOS, nNOS, or iNOS genes on the initiation phase of caerulein-induced AP in mice using in vivo and in vitro models. Western blot analysis was performed to assess eNOS phosphorylation status, an indicator of enzyme activity, and microsphere studies were used to measure PMBF. l-NNA and eNOS deletion, but not nNOS or iNOS deletion, increased pancreatic trypsin activity and serum lipase during the initiation phase of in vivo caerulein-induced AP. l-NNA and eNOS did not affect trypsin activity in caerulein-hyperstimulated isolated acini, suggesting that nonacinar events mediate the effect of NOS blockade in vivo. The initiation phase of AP in wild-type mice was associated with eNOS Thr495 residue dephosphorylation, which accompanies eNOS activation, and a 178% increase in PMBF; these effects were absent in eNOS-deleted mice. Thus eNOS is the main isoform influencing the initiation of caerulein-induced AP. eNOS-derived NO exerts a protective effect through actions on nonacinar cell types, most likely endothelial cells, to produce greater PMBF.

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