Reaction of a tumour-associated trypsin inhibitor with serine proteinases associated with coagulation and tumour invasion.
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ABSTRACT:
SUBMITTER: Turpeinen U
PROVIDER: S-EPMC1135171 | biostudies-other | 1988 Sep
REPOSITORIES: biostudies-other
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Project description:Seven arginylfluoroalkanes ('arginine fluoroalkyl ketones') were synthesized by using a modified Dakin-West procedure. The structure of benzoyl-Arg-CF2CF3 was analysed by 19F-n.m.r. spectroscopy and m.s. and the compound was shown to exist primarily as a hydrate or cyclic carbinolamine. Arginylfluoroalkanes are good inhibitors of blood-coagulation serine proteinases and were found to be slow-binding inhibitors for bovine trypsin with Ki values of 0.2-56 microM. Benzoyl-Arg-CF2CF3 was the best inhibitor for bovine thrombin and human Factor XIa, and inhibited thrombin and Factor XIa competitively with Ki values of 13 microM and 62 microM respectively. The best inhibitor for pig pancreatic kallikrein was p-toluoyl-Arg-CF3, with a Ki value of 35 microM. Benzoyl-Arg-CF3 and benzoyl-Arg-CF2CF3 inhibited human plasma kallikrein competitively, with Ki values of 50 microM. None of the seven arginylfluoroalkanes was a good inhibitor of human factor Xa or of Factor XIIa. The arginylfluoroalkanes were tested in the prothrombin time (PT) and activated partial thromboplastin time (APTT) coagulant assays. Two fluoroketones, benzoyl-Arg-CF2CF3 and 1-naphthoyl-Arg-CF3, had significant anticoagulant activity. Benzoyl-Arg-CF2CF3 was found to prolong the PT 1.8-fold at 120 microM and to prolong the APTT 2.4-fold at 90 microM, whereas 1-naphthoyl-Arg-CF3 only prolonged the APTT 1.7-fold at 100 microM.
| S-EPMC1136917 | biostudies-other
Project description:The effects of the Ca2+-activated cysteine proteinase, the rat trypsin-like serine proteinase and bovine trypsin on myofibrillar proteins from rabbit skeletal muscle are compared. 2. Myofibrils that had been treated at neutral pH with the Ca2+-dependent proteinase and with the rat enzyme were (a) analyzed by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis and (b) examined in the electron microscope. Treatment with each proteinase resulted in the loss of the Z-discs, but the rat enzyme caused much more extensive disruption of the ultrastructure and degraded more of the myofibrillar proteins. 3. Purified F-actin was almost totally resistant to the proteinases, whereas G-actin was degraded by the rat trypsin-like proteinase at a rate approx. 15 times faster than was obtained with bovine trypsin. 4. Similar results were obtained with alpha-actinin, whereas tropomyosin was degraded more readily by bovine trypsin than by the rat trypsin-like proteinase. 5. The implications of these findings for the non-lysosomal breakdown of myofibrillar proteins in vivo are considered.
| S-EPMC1163641 | biostudies-other
Project description:Lipoprotein-associated coagulation inhibitor (LACI) inhibits activated Factor X (Xa) directly and, in an Xa-dependent fashion, inhibits Factor VIIa-tissue factor (TF), presumably by forming a quaternary Xa-LACI-VIIa-TF complex. LACI isolated from the conditioned media of HepG2 cells grown in the presence of [32P]orthophosphate was observed to be covalently phosphorylated. Dephosphorylation of 32P-LACI with phosphatase resulted in an almost complete removal of the radiolabel. Phosphoamino acid analysis of the purified 32P-LACI established that the phosphorylation occurred on (a) serine residue(s). At its N-terminus, LACI contains a cluster of acidic residues C-terminal to the serine-2 residue. Such a site is characteristic of the sites phosphorylated by casein kinase II (CKII) in protein substrates. Edman degradation of endogenously labelled 32P-LACI revealed that the serine-2 residue was a major site of phosphorylation. Phosphorylation of purified LACI by bovine CKII was observed to occur in vitro; amino acid sequence analysis demonstrated that CKII phosphorylated LACI at the serine-2 residue. Recombinant LACI expressed from mouse C127 fibroblasts transfected using a bovine-papilloma-virus expression vector was found to be endogenously phosphorylated. By using site-directed mutagenesis, an altered form of LACI was produced in which the serine-2 residue had been changed to alanine. This altered LACI, although expressed in similar quantity to the wild-type LACI, was not detectably phosphorylated. Using the altered LACI in functional studies demonstrated that a serine residue at position 2, and thus the phosphorylation of this site, was not essential for LACI's inhibition of Xa and VIIa-TF activities.
| S-EPMC1131777 | biostudies-other
Project description:1. Hydrolysis of the myosins from smooth and from skeletal muscle by a rat trypsin-like serine proteinase and by bovine trypsin at pH 7 is compared. 2. Proteolysis of the heavy chains of both myosins by the rat enzyme proceeds at rates approx. 20 times faster than those obtained with bovine trypsin. Whereas cleavage of skeletal-muscle myosin heavy chain by both enzymes results in the generation of conventional products i.e. heavy meromyosin and light meromyosin, the heavy chain of smooth-muscle myosin is degraded into a fragment of mol. wt. 150000. This is dissimilar from heavy meromyosin and cannot be converted into heavy meromyosin. It is shown that proteolysis of the heavy chain takes place in the head region. 3. The 'regulatory' light chain (20kDa) of smooth-muscle myosin is degraded very rapidly by the rat proteinase. 4. The ability of smooth-muscle myosin to have its ATPase activity activated by actin in the presence of a crude tropomyosin fraction on introduction of Ca2+ is diminished progressively during exposure to the rat proteinase. The rate of loss of the Ca2+-activated actomyosin ATPase activity is very similar to the rate observed for proteolysis of the heavy chain and 3-4 times slower than the rate of removal of the so-called 'regulatory' light chain. 5. The significance of these findings in terms of the functional organization of the smooth muscle myosin molecule is discussed. 6. Since the degraded myosin obtained after exposure to very small amounts of the rat proteinase is no longer able to respond to Ca2+, i.e. the functional activity of the molecule has been removed, the implications of a similar type of proteolysis operating in vivo are considered for myofibrillar protein turnover in general, but particularly with regard to the initiation of myosin degradation, which is known to take place outside the lysosome (i.e. at neutral pH).
| S-EPMC1163640 | biostudies-other
Project description:BackgroundThere is an insufficient number of reliable prognostic and response predictive biomarkers in colorectal cancer (CRC) management. In a previous study, we found that high tumour tissue expression of tumour-associated trypsin inhibitor (TATI) correlated with liver metastasis and an impaired prognosis in CRC. The aim of this study was to investigate the prognostic validity of serum TATI (s-TATI) in CRC. We further assessed the prognostic value of carcino-embryonic antigen in serum (s-CEA) and the interrelationship between s-TATI and TATI in tissue (t-TATI).MethodsUsing an immunofluorometric assay, s-TATI levels were analysed in 334 preoperatively collected serum samples from patients with CRC. Spearman's Rho and Chi-square test were used for analysis of correlations between s-TATI and clinicopathological parameters, s-CEA and t-TATI. Kaplan-Meier analysis and Cox uni- and multivariate regression analysis were used to estimate disease free survival (DFS) and overall survival (OS) according to quartiles of s-TATI and cut-offs derived from ROC-analysis of s-TATI and s-CEA.ResultsIncreased levels of s-TATI were associated with a reduced DFS (HR = 2.00; 95% CI 1.40-2.84, P < 0.001) and OS (HR = 2.40; 95% CI 1.74-3.33, P < 0.001). (HR = 2.89; 95% CI 1.96-4.25). This association remained significant in multivariate analysis. The association for OS remained significant in multivariate analysis (HR = 1.51; 95% CI 1.03-2.22, P = 0.034 for DFS and HR = 1.78; 95% CI 1.25-2.53, P = 0.001 for OS). There was no significant association between s-TATI and t-TATI. The prognostic value of s-CEA was also evident, but somewhat weaker than for s-TATI.ConclusionsHigh preoperative s-TATI levels predict a poor prognosis in patients with CRC, and the prognostic value is independent of established prognostic parameters and t-TATI expression. These data suggest that s-TATI might be a useful marker for prognostic stratification in CRC.
| S-EPMC2946315 | biostudies-literature
Project description:Atomic resolution structures of trypsin acyl-enzymes and a tetrahedral intermediate analog, along with previously solved structures representing the Michaelis complex, are used to reconstruct events in the catalytic cycle of this classic serine protease. Structural comparisons provide insight into active site adjustments involved in catalysis. Subtle motions of the catalytic serine and histidine residues coordinated with translation of the substrate reaction center are seen to favor the forward progress of the acylation reaction. The structures also clarify the attack trajectory of the hydrolytic water in the deacylation reaction.
| S-EPMC1458980 | biostudies-literature
Project description:In order to extend the scope for the application of acyl-enzymes as fibrinolytic agents, p-amidinophenyl ester enzyme substrates were prepared that gave stabilized acyl-enzymes capable of being coupled to other proteins. Coupling was achieved by reaction of protein thiol functions with a 2-pyridyldithio moiety within the acyl group. Acyl-enzymes derived from such substrates were stable enough to permit isolation of reversible conjugates between proteins and the active centres of plasminogen activators. Hydrolytic release of active enzyme from a conjugate of human immunoglobulin G and urokinase could be demonstrated.
| S-EPMC1148556 | biostudies-other
Project description:BackgroundDermatomyositis and polymyositis are the best known idiopathic inflammatory myopathies (IIMs). Classic histopathologic findings include the infiltration of inflammatory cells into muscle tissues. Neutrophil serine proteinases (NSPs) are granule-associated enzymes and play roles in inflammatory cell migration by increasing the permeability of vascular endothelial cells. In this study, we aimed to find the roles of NSPs in pathogenesis of IIMs.MethodsRNA and DNA were isolated to measure the relative expression of NSPs and their methylation levels. The expression of NSPs in serum and muscle tissues was tested by enzyme-linked immunosorbent assay, immunohistochemistry, and immunofluorescence, respectively. Serum from patients was used to culture the human dermal microvascular endothelial cells (HDMECs), and then we observed the influence of serum on expression of VE-cadherin, endothelial cell tube formation, and transendothelial migration of peripheral blood mononuclear cells (PBMCs).ResultsWe found that the expression of NSPs was increased in PBMCs, serum, and muscle tissues of IIM patients; these NSPs were hypomethylated in the PBMCs of patients. Serum NSPs were positively correlated with clinical indicators of IIM patients, including lactic dehydrogenase, erythrocyte sedimentation rate, C-reactive protein, immunoglobulin G, immunoglobulin M, and immunoglobulin A. Patients with anti-Jo-1, with anti-Ro-52, or without interstitial lung disease had lower levels of proteinase 3. Serum NSPs degraded the VE-cadherin of HDMECs, and serum NSP application increased the permeability of HDMECs.ConclusionsOur studies indicate, for the first time, that NSPs play an important role in muscle inflammatory cell infiltration by increasing the permeability of vascular endothelial cells in IIM patients.
| S-EPMC6034343 | biostudies-literature
Project description:BackgroundWe have previously demonstrated that elevated concentrations of tumour-associated trypsin inhibitor (TATI) in both tumour tissue (t-TATI) and in serum (s-TATI) are associated with a poor prognosis in colorectal cancer patients. It was also found that s-TATI concentrations were lower in patients with rectal cancer compared to patients with colon cancer. In this study, we investigated the effects of neoadjuvant radiotherapy (RT) on concentrations of t-TATI and s-TATI in patients with rectal cancer.MethodsTATI was analysed in serum, normal mucosa and tumour tissue collected at various time points in 53 rectal cancer patients enrolled in a case-control study where 12 patients received surgery alone, 20 patients 5 × 5 Gy (short-term) preoperative RT and 21 patients 25 × 2 Gy (long-term) preoperative RT. T-TATI was analysed by immunohistochemistry and s-TATI was determined by an immunofluorometric assay. Mann-Whitney U test and Wilcoxon Z (Z) test were used to assess t-TATI and s-TATI concentrations in relation to RT. Spearman's correlation (R) test was used to explore the associations between t-TATI, s-TATI and clinicopathological parameters. Overall survival (OS) according to high and low t-TATI and s-TATI concentrations was estimated by classification and regression tree analysis, Kaplan-Meier analysis and the log rank test.ResultsRT did not affect concentrations of t-TATI or s-TATI. In patients receiving short-term but not long-term RT, s-TATI concentrations were significantly higher 4 weeks post surgery than in serum drawn prior to surgery (Z = -3.366, P < 0.001). T-TATI expression correlated with male gender (R = 0.406, P = 0.008). High t-TATI expression in surgical specimens was associated with a significantly shorter OS (P = 0.045). S-TATI concentrations in serum drawn at all time points were associated with an impaired OS (P = 0.035 before RT, P = 0.001 prior to surgery, P = 0.043 post surgery). At all time points, s-TATI correlated with higher age (P < 0.001-0.021) and with increased s-creatinine concentrations assessed prior to surgery (P = 0.041).ConclusionsThe results presented here further validate the utility of t-TATI and s-TATI as prognostic biomarkers in patients with rectal cancer, independent of neoadjuvant RT.
| S-EPMC3173337 | biostudies-literature
Project description:A series of novel synthetic dipeptides, containing a C-terminal glyoxal grouping (-COCHO), have been tested as inhibitors against typical members of the serine- and cysteine-proteinase families. For example, the sequences benzyloxycarbonyl (Cbz)-Pro-Phe-CHO (I) and Cbz-Phe-Ala-CHO (II), which fulfil the known primary and secondary specificity requirements of chymotrypsin and cathepsin B respectively, have been found to be potent reversible inhibitors of their respective target proteinase. Thus I was found to inhibit chymotrypsin with a Ki of approximately 0.8 microM, whereas II exhibits a Ki of approximately 80 nm against cathepsin B. These Ki values are some 10-fold and 3-fold lower than those reported for the corresponding peptide-aldehyde inhibitors of chymotrypsin and cathepsin B upon which the peptidyl-glyoxals were fashioned. Unexpectedly, the sequence Cbz-Pro-Ala-CHO, which was designed to inhibit elastase-like proteinases, exhibited no inhibitory activity towards porcine pancreatic elastase, even when used at concentrations as high as 200 microM.
| S-EPMC1134361 | biostudies-other