scholarly journals Trypsin inhibition by ferrocene

2005 ◽  
pp. 203-213 ◽  
Author(s):  
Zoran Kukric ◽  
Mirjana Zabic
Keyword(s):  
Transition Metals ◽  
Transition State ◽  
Active Site ◽  
Inhibitory Activity ◽  
Inhibitory Effect ◽  
Trypsin Activity ◽  
Sandwich Compounds ◽  
Trypsin Inhibition ◽  
The Family ◽  
Direct Binding

Many transition metals and their complexes show inhibitory effect on someproteolytic enzymes, including trypsin. Their inhibitory activity is based on the direct binding to the active site of trypsin, mimicking formation of a five-coordinate transition state required for the reaction. The influence of ferrocene on trypsin activity using N-?-benzoyl-DL-arginine p-nitroanilide as a substrate was investigated. Ferrocene was selected as a potential inhibitor because it belongs to the family oforganometallic, so called "sandwich " compounds, and its cyclopentadienyl rings might have an appropriate geometry. It was found that ferrocene decreases trypsin activity and the K. for ferrocene was found to be 39.8.

scholarly journals Transition state mimics are valuable mechanistic probes for structural studies with the arginine methyltransferase CARM1

2017 ◽  
Vol 114 (14) ◽  
pp. 3625-3630 ◽  
Author(s):  
Matthijs J. van Haren ◽  
Nils Marechal ◽  
Nathalie Troffer-Charlier ◽  
Agostino Cianciulli ◽  
Gianluca Sbardella ◽  
...  
Keyword(s):  
Transition State ◽  
Active Site ◽  
Arginine Methylation ◽  
Eukaryotic Cells ◽  
Structural Studies ◽  
Potential Therapeutic Target ◽  
Arginine Methyltransferase ◽  
Transient Nature ◽  
The Family ◽  
Covalently Linked

Coactivator associated arginine methyltransferase 1 (CARM1) is a member of the protein arginine methyltransferase (PRMT) family and methylates a range of proteins in eukaryotic cells. Overexpression of CARM1 is implicated in a number of cancers, and it is therefore seen as a potential therapeutic target. Peptide sequences derived from the well-defined CARM1 substrate poly(A)-binding protein 1 (PABP1) were covalently linked to an adenosine moiety as in the AdoMet cofactor to generate transition state mimics. These constructs were found to be potent CARM1 inhibitors and also formed stable complexes with the enzyme. High-resolution crystal structures of CARM1 in complex with these compounds confirm a mode of binding that is indeed reflective of the transition state at the CARM1 active site. Given the transient nature of PRMT–substrate complexes, such transition state mimics represent valuable chemical tools for structural studies aimed at deciphering the regulation of arginine methylation mediated by the family of arginine methyltransferases.

scholarly journals Design and synthesis of novel pyrazole-benzofuran hybrids: in vitro α-glucosidase inhibitory activity, kinetic and molecular modeling study

2021 ◽  
Author(s):  
Fateme Azimi ◽  
Homa Azizian ◽  
Mohammad Najafi ◽  
Ghadamali khodarahmi ◽  
Motahareh hassanzadeh ◽  
...  
Keyword(s):  
Active Site ◽  
Inhibitory Activity ◽  
Inhibitory Effect ◽  
Back Side ◽  
Binding Interaction ◽  
Dynamic Simulations ◽  
Standard Drug ◽  
Design And Synthesis ◽  
Derivatives Of

Abstract In this work, new derivatives of biphenyl pyrazole-benzofuran hybrids designed, synthesized and evaluated in vitro through enzymatic assay for inhibitory effect against α-glucosidase activity. Newly identified inhibitors were found to be four to eighteen folds more active with IC50 values in the range of 40.6 ± 0.2–164.3 ± 1.8 µM, as compared to the standard drug acarbose (IC50 = 750.0 ± 10.0 µM). Limited Structure-activity relationship was established. A kinetic binding study indicated that most active compound 8e acted as the competitive inhibitors of α-glucosidase with Ki = 38 µM. Molecular docking has also been performed to find the interaction modes responsible for the desired inhibitory activity. As expected, all pharmacophoric features used in the design of the hybrid, are involved in the interaction with the active site of the enzyme. In addition, molecular dynamic simulations showed compound 8e oriented vertically into the active site from mouth to the bottom and stabilized the enzyme domains by interacting with the interface of domain A and domain B and the back side of the active site while acarbose formed non-binding interaction with the residue belong to the domain A of the enzyme.

Abstract 30: Tissue Factor Pathway Inhibitor α Inhibits Prothrombinase via a Three-Step Mechanism

2017 ◽  
Vol 37 (suppl_1) ◽  
Author(s):  
Jeremy P Wood ◽  
Alan E Mast
Keyword(s):  
Active Site ◽  
Inhibitory Activity ◽  
Thrombin Generation ◽  
Platelet Rich Plasma ◽  
Factor Xa ◽  
Prothrombinase Complex ◽  
Factor Va ◽  
Direct Binding ◽  
Affinity Interaction

TFPIα inhibits early forms of the prothrombinase complex (factor Xa (FXa), factor Va (FVa)), though the inhibitory mechanism is not entirely understood. One step of inhibition is a high affinity interaction between a TFPIα C-terminal basic region (BR) (252-LIKTKRKRKK-261) and an acidic region (AR) present in FXa-activated and platelet-released forms of FVa. We investigated two additional potential mechanistic steps: (1) binding of the second Kunitz-type inhibitory domain (K2) of TFPIα to the FXa active site; and (2) the function of uncharged residues L252, I253, and T255 within the BR, which are evolutionarily conserved, suggesting they have activity. Direct inhibition of FXa was investigated using TFPIα with an altered K2 (TFPI-R107A) incapable of binding FXa. TFPI-R107A inhibited purified prothrombinase 17-fold weaker than TFPIα (IC50 = 30.6nM vs. 1.8nM) and did not inhibit FXa-initiated thrombin generation in platelet-rich plasma (PRP). Therefore, direct binding of FXa and K2 is required for efficient inhibition of prothrombinase under physiological conditions. Similarly, the role of L252, I253, and T255 was investigated by substituting them with alanine (TFPI-AAKA). The IC50 for prothrombinase inhibition by TFPI-AAKA was 10.4nM, and it had reduced inhibitory activity in PRP, revealing that these residues are also required for efficient prothrombinase inhibition. The role of L252, I253, and T255 was further probed using the peptide LIKTKRKRKK, which inhibited purified prothrombinase (IC50 = 1.0μM) and thrombin generation in PRP at 1μM. AAKAKRKRKK had very little activity in either assay (~20% prothrombinase inhibition with 225μM peptide), but bound the FVa AR equivalently to LIKTKRKRKK (K d = 5.9nM and 6.0nM, respectively). Thus, the basic residues are responsible for AR binding, while a second step, mediated by L252-T255, is necessary for inhibitory activity. These residues may be necessary for displacement of FXa from FVa, as proposed by Bunce et al. We propose that prothrombinase inhibition by TFPIα involves three steps: (1) the TFPIα BR basic residues bind the FVa AR; (2) residues L252-T255 block prothrombinase assembly; and (3) K2 binds the FXa active site. All three steps are required for physiologic inhibition of prothrombinase by TFPIα.

Characterization of an Abnormal Antithrombin (Milano 2) with Defective Thrombin Binding

1986 ◽  
Vol 56 (03) ◽  
pp. 349-352 ◽  
Author(s):  
A Tripodi ◽  
A Krachmalnicoff ◽  
P M Mannucci
Keyword(s):  
Venous Thromboembolism ◽  
Active Site ◽  
Inhibitory Activity ◽  
Antithrombin Iii ◽  
Factor Xa ◽  
Molecular Defect ◽  
Affinity Adsorption ◽  
Italian Family ◽  
Crossed Immunoelectrophoresis

SummaryFour members of an Italian family (two with histories of venous thromboembolism) had a qualitative defect of antithrombin III reflected by normal antigen concentrations and halfnormal antithrombin activity with or without heparin. Anti-factor Xa activities were consistently borderline low (about 70% of normal). For the propositus’ plasma and serum the patterns of antithrombin III in crossed-immunoelectrophoresis with or without heparin were indistinguishable from those of normal plasma or serum. A normal affinity of antithrombin III for heparin was documented by heparin-sepharose chromatography. Affinity adsorption of the propositus’ plasma to human α-thrombin immobilized on sepharose beads revealed defective binding of the anti thrombin III to thrombin-sepharose. Hence the molecular defect of this variant appears to be at the active site responsible for binding and neutralizing thrombin, thus accounting for the low thrombin inhibitory activity.

scholarly journals 1250. Novel Boronic Acid Transition State Analogs (BATSI) with in vitro inhibitory activity against class A, B and C β-lactamases

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S643-S643
Author(s):  
Maria F Mojica ◽  
Christopher Bethel ◽  
Emilia Caselli ◽  
Magdalena A Taracila ◽  
Fabio Prati ◽  
...  
Keyword(s):  
Active Site ◽  
Inhibitory Activity ◽  
Covalent Bond ◽  
Thiol Group ◽  
Viable Cell ◽  
Free Thiol ◽  
Transition State Analogs ◽  
Cell Counts ◽  
Free Thiol Group

Abstract Background Catalytic mechanisms of serine β-lactamases (SBL; classes A, C and D) and metallo-β-lactamases (MBLs) have directed divergent strategies towards inhibitor design. SBL inhibitors act as high affinity substrates that -as in BATSIs- form a reversible, dative covalent bond with the conserved active site Ser. MBL inhibitors bind the active-site Zn2+ ions and displace the nucleophilic OH-. Herein, we explore the efficacy of a series of BATSI compounds with a free-thiol group at inhibiting both SBL and MBL. Methods Exploratory compounds were synthesized using stereoselective homologation of (+) pinandiol boronates to introduce the amino group on the boron-bearing carbon atom, which was subsequently acylated with mercaptopropanoic acid. Representative SBL (KPC-2, ADC-7, PDC-3 and OXA-23) and MBL (IMP-1, NDM-1 and VIM-2) were purified and used for the kinetic characterization of the BATSIs. In vitro activity was evaluated by a modified time-kill curve assay, using SBL and MBL-producing strains. Results Kinetic assays revealed that IC50 values ranged from 1.3 µM to >100 µM for this series. The best compound, s08033, demonstrated inhibitory activity against KPC-2, VIM-2, ADC-7 and PDC-3, with IC50 in the low μM range. Reduction of at least 1.5 log10-fold of viable cell counts upon exposure to sub-lethal concentrations of antibiotics (AB) + s08033, compared to the cells exposed to AB alone, demonstrated the microbiological activity of this novel compound against SBL- and MBL-producing E. coli (Table 1). Table 1 Conclusion Addition of a free-thiol group to the BATSI scaffold increases the range of these compounds resulting in a broad-spectrum inhibitor toward clinically important carbapenemases and cephalosporinases. Disclosures Robert A. Bonomo, MD, Entasis, Merck, Venatorx (Research Grant or Support)

scholarly journals Inhibitory Effects of Secondary Metabolites from the Lichen Stereocaulon evolutum on Protein Tyrosine Phosphatase 1B

Planta Medica ◽  
2021 ◽  
Author(s):  
Birgit Waltenberger ◽  
Françoise Lohézic-Le Dévéhat ◽  
Thi Huyen Vu ◽  
Olivier Delalande ◽  
Claudia Lalli ◽  
...  
Keyword(s):  
Protein Tyrosine Phosphatase ◽  
Inhibitory Activity ◽  
Tyrosine Phosphatase ◽  
Inhibitory Effect ◽  
Positive Control ◽  
Protein Tyrosine Phosphatase 1B ◽  
Protein Tyrosine ◽  
Ic50 Values ◽  
A Cell

AbstractProtein tyrosine phosphatase 1B plays a significant role in type 2 diabetes mellitus and other diseases and is therefore considered a new drug target. Within this study, an acetone extract from the lichen Stereocaulon evolutum was identified to possess strong protein tyrosine phosphatase 1B inhibition in a cell-free assay (IC50 of 11.8 µg/mL). Fractionation of this bioactive extract led to the isolation of seven known molecules belonging to the depsidones and the related diphenylethers and one new natural product, i.e., 3-butyl-3,7-dihydroxy-5-methoxy-1(3H)-isobenzofurane. The isolated compounds were evaluated for their inhibition of protein tyrosine phosphatase 1B. Two depsidones, lobaric acid and norlobaric acid, and the diphenylether anhydrosakisacaulon A potently inhibited protein tyrosine phosphatase 1B with IC50 values of 12.9, 15.1, and 16.1 µM, respectively, which is in the range of the protein tyrosine phosphatase 1B inhibitory activity of the positive control ursolic acid (IC50 of 14.4 µM). Molecular simulations performed on the eight compounds showed that i) a contact between the molecule and the four main regions of the protein is required for inhibitory activity, ii) the relative rigidity of the depsidones lobaric acid and norlobaric acid and the reactivity related to hydrogen bond donors or acceptors, which interact with protein tyrosine phosphatase 1B key amino acids, are involved in the bioactivity on protein tyrosine phosphatase 1B, iii) the cycle opening observed for diphenylethers decreased the inhibition, except for anhydrosakisacaulon A where its double bond on C-8 offsets this loss of activity, iv) the function present at C-8 is a determinant for the inhibitory effect on protein tyrosine phosphatase 1B, and v) the more hydrogen bonds with Arg221 there are, the more anchorage is favored.

scholarly journals Targeting SARS-CoV-2 Polymerase with New Nucleoside Analogues

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3461
Author(s):  
Vasiliki Daikopoulou ◽  
Panagiotis Apostolou ◽  
Sofia Mourati ◽  
Ioanna Vlachou ◽  
Maria Gougousi ◽  
...  
Keyword(s):  
Inhibitory Activity ◽  
Drug Repositioning ◽  
Nucleoside Analogues ◽  
In Vitro Assays ◽  
Rna Dependent Rna Polymerase ◽  
Sugar Moiety ◽  
The Family ◽  
Approved Drugs ◽  
Fda Approved Drugs

Despite the fact that COVID-19 vaccines are already available on the market, there have not been any effective FDA-approved drugs to treat this disease. There are several already known drugs that through drug repositioning have shown an inhibitory activity against SARS-CoV-2 RNA-dependent RNA polymerase. These drugs are included in the family of nucleoside analogues. In our efforts, we synthesized a group of new nucleoside analogues, which are modified at the sugar moiety that is replaced by a quinazoline entity. Different nucleobase derivatives are used in order to increase the inhibition. Five new nucleoside analogues were evaluated with in vitro assays for targeting polymerase of SARS-CoV-2.

scholarly journals Identification and Target-Modification of SL-BBI: A Novel Bowman–Birk Type Trypsin Inhibitor from Sylvirana latouchii

Biomolecules ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1254 ◽  
Author(s):  
Xi Chen ◽  
Dong Chen ◽  
Linyuan Huang ◽  
Xiaoling Chen ◽  
Mei Zhou ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Trypsin Inhibitor ◽  
Inhibitory Activity ◽  
Membrane Damage ◽  
Antiproliferative Effects ◽  
Docking Simulations ◽  
Cell Membrane Damage ◽  
Action Mode ◽  
Trypsin Inhibition ◽  
Cloning Method

The peptides from the ranacyclin family share similar active disulphide loop with plant-derived Bowman–Birk type inhibitors, some of which have the dual activities of trypsin inhibition and antimicrobial. Herein, a novel Bowman–Birk type trypsin inhibitor of the ranacyclin family was identified from the skin secretion of broad-folded frog (Sylvirana latouchii) by molecular cloning method and named as SL-BBI. After chemical synthesis, it was proved to be a potent inhibitor of trypsin with a Ki value of 230.5 nM and showed weak antimicrobial activity against tested microorganisms. Modified analogue K-SL maintains the original inhibitory activity with a Ki value of 77.27 nM while enhancing the antimicrobial activity. After the substitution of active P1 site to phenylalanine and P2′ site to isoleucine, F-SL regenerated its inhibitory activity on chymotrypsin with a Ki value of 309.3 nM and exhibited antiproliferative effects on PC-3, MCF-7 and a series of non-small cell lung cancer cell lines without cell membrane damage. The affinity of F-SL for the β subunits in the yeast 20S proteasome showed by molecular docking simulations enriched the understanding of the possible action mode of Bowman–Birk type inhibitors. Further mechanistic studies have shown that F-SL can activate caspase 3/7 in H157 cells and induce apoptosis, which means it has the potential to become an anticancer agent.

Growth-Inhibiting Properties of Xylem Exudate From Vitis vinifera

1995 ◽  
Vol 22 (1) ◽  
pp. 7 ◽  
Author(s):  
JA Campbell ◽  
BR Loveys ◽  
VWK Lee ◽  
S Strother
Keyword(s):  
Vitis Vinifera ◽  
Inhibitory Activity ◽  
Lemna Minor ◽  
Growth Inhibitor ◽  
Inhibitory Effect ◽  
Vitis Vinifera L ◽  
Inhibitory Effects ◽  
Inhibitor Activity ◽  
Xylem Exudate ◽  
Growth Inhibiting

An inhibitory effect on the growth of Lemna minor L. cultures has been demonstrated in xylem exudate from Vitis vinifera L. var. Waltham Cross bled from canes cut near the time of budburst. Most inhibitory activity was detected up to the time of maximal daily exudation, which corresponded closely with budburst. After this time the inhibitory activity rapidly disappeared. A similar pattern occurred in each of the 3 years of the study, 1988-1990. Using ultrafiltration, it was shown that most of the growth inhibitor activity of the crude exudate was located in the 0.5-10 kDa fraction. This fraction exhibited a seasonal variation in its bioactivity similar to that ofthe crude exudate samples. The 0.5-10 kDa fraction was found to contain abscisic acid but not in a sufficient quantity to account for the inhibitory effects. When chromatographically separated fractions corresponding to oligosaccharides were pooled, biological activity equivalent to that of the crude exudate was retained, which provides evidence that the inhibitor is possibly an oligosaccharide.

scholarly journals Inhibition of pancreatic lipase in vitro by the covalent inhibitor tetrahydrolipstatin

1988 ◽  
Vol 256 (2) ◽  
pp. 357-361 ◽  
Author(s):  
P Hadváry ◽  
H Lengsfeld ◽  
H Wolfer
Keyword(s):  
Transition State ◽  
Acid Derivative ◽  
Pancreatic Lipase ◽  
Active Site ◽  
Boronic Acid ◽  
Selective Inhibitor ◽  
Covalent Intermediate ◽  
State Form ◽  
Covalent Inhibitor

Tetrahydrolipstatin inhibits pancreatic lipase from several species, including man, with comparable potency. The lipase is progressively inactivated through the formation of a long-lived covalent intermediate, probably with a 1:1 stoichiometry. The lipase substrate triolein and also a boronic acid derivative, which is presumed to be a transition-state-form inhibitor, retard the rate of inactivation. Therefore, in all probability, tetrahydrolipstatin reacts with pancreatic lipase at, or near, the substrate binding or active site. Tetrahydrolipstatin is a selective inhibitor of lipase; other hydrolases tested were at least a thousand times less potently inhibited.

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