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Biomolecules Jul 2019Anuran amphibian skin secretions are a rich source of peptides, many of which represent novel protease inhibitors and can potentially act as a source for protease...
Anuran amphibian skin secretions are a rich source of peptides, many of which represent novel protease inhibitors and can potentially act as a source for protease inhibitor drug discovery. In this study, a novel bioactive Bowman-Birk type inhibitory hexadecapeptide of the Ranacyclin family from the defensive skin secretion of the Fukien gold-striped pond frog, , was successfully isolated and identified, named PPF-BBI. The primary structure of the biosynthetic precursor was deduced from a cDNA sequence cloned from a skin-derived cDNA library, which contains a consensus motif representative of the Bowman-Birk type inhibitor. The peptide was chemically synthesized and displayed a potent inhibitory activity against trypsin (Ki of 0.17 µM), as well as an inhibitory activity against tryptase (Ki of 30.73 µM). A number of analogues of this peptide were produced by rational design. An analogue, which substituted the lysine (K) at the predicted P position with phenylalanine (F), exhibited a potent chymotrypsin inhibitory activity (Ki of 0.851 µM). Alternatively, a more potent protease inhibitory activity, as well as antimicrobial activity, was observed when P was replaced by lysine, forming K-PPF-BBI. The addition of the cell-penetrating peptide Tat with a trypsin inhibitory loop resulted in a peptide with a selective inhibitory activity toward trypsin, as well as a strong antifungal activity. This peptide also inhibited the growth of two lung cancer cells, H460 and H157, demonstrating that the targeted modifications of this peptide could effectively and efficiently alter its bioactivity.
Topics: Antifungal Agents; Drug Design; Gene Library; Protease Inhibitors
PubMed: 31337113
DOI: 10.3390/biom9070280 -
Acta Oto-laryngologica 1987Protease and antiprotease activities were estimated in nasal secretions from patients with chronic sinusitis and nasal allergy, using [3H]-casein as substrate. In the...
Protease and antiprotease activities were estimated in nasal secretions from patients with chronic sinusitis and nasal allergy, using [3H]-casein as substrate. In the purulent nasal secretions, strong protease activity was measured, but there was less activity in the allergic nasal secretions. In contrast, trypsin inhibitory activity in allergic nasal secretions was much higher than in nasal secretions from the patients with chronic sinusitis. A protease inhibitor was partially isolated from nasal secretions of the nasal allergic patients by Sephadex G-150 gel chromatography and characterized. This protease inhibitor has an apparent molecular weight of 10,000 D, determined by SDS-polyacrylamidegel electrophoresis. It depresses the activities of bovine pancreatic trypsin, bovine pancreatic chymotrypsin and proteases in nasal purulent secretions, whereas it does not inhibit porcine pancreatic elastase, papain, or human plasmin.
Topics: Chronic Disease; Humans; Paranasal Sinuses; Peptide Hydrolases; Protease Inhibitors; Sinusitis
PubMed: 3324629
DOI: 10.3109/00016488709128286 -
Daru : Journal of Faculty of Pharmacy,... Jun 2022Vortioxetine an anti-depressant FDA-drug recently reported showing better in vitro efficacy against SARS-CoV-2.
PURPOSE
Vortioxetine an anti-depressant FDA-drug recently reported showing better in vitro efficacy against SARS-CoV-2.
METHODS
In this study, we have synthesized ten new derivatives having alkenes, alkynes, benzyl, aryl, and mixed carbamate at the N-terminal of vortioxetine. Then the binding energy and interactions with the crucial amino acid residues in the binding pocket of main protease (M) of SARS-CoV-2, of reported and ten newly synthesized vortioxetine derivatives (total thirty-one) in comparison with remdesivir are analyzed and presented in this paper.
RESULTS
Based on the docking scores predicted by ADV and AD, most vortioxetine derivatives showed better binding efficiency towards M of SARS-CoV-2 in comparison with remdesivir (an EUA approved drug against SARS-CoV-2 M) and vortioxetine.
CONCLUSION
This study shows that some vortioxetine derivatives can be developed into promising drugs for COVID-19 treatment.
Topics: Antiviral Agents; Coronavirus 3C Proteases; Humans; Molecular Docking Simulation; Molecular Dynamics Simulation; Protease Inhibitors; SARS-CoV-2; Vortioxetine; COVID-19 Drug Treatment
PubMed: 35508799
DOI: 10.1007/s40199-022-00441-z -
Expert Review of Pharmacoeconomics &... Jun 2012Protease inhibitor with pegylated interferon and ribavirin therapy (PI-PR) increases hepatitis C virus treatment efficacy versus standard of care pegylated interferon... (Comparative Study)
Comparative Study Review
Protease inhibitor with pegylated interferon and ribavirin therapy (PI-PR) increases hepatitis C virus treatment efficacy versus standard of care pegylated interferon and ribavarin therapy [PR]. The adverse event (AE) impact of PI-PR remains under-reported. The authors estimated the AE impact on costs, treatment discontinuation and health-related quality of life (HRQoL) in PI-PR- and PR-treated patients through literature review and cost analysis. HRQoL and safety data were synthesized by instrument, AE and discontinuation rate. AE-related treatment costs were estimated with trial-based AE rates and literature-based protocols, resource utilization and standard costs. No PI-PR study reported HRQoL outcomes. Five PR studies reported that anemia, depression, fatigue and/or influenza-like symptoms negatively affected HRQoL. Decreased HRQoL predicted treatment discontinuation in two PR studies. PI-PR and PR had comparable AE-related treatment discontinuation rates (~12%). Weighted AE-related treatment costs were US$2042, $1835 and $1076 in boceprevir-based PI-PR, PR and telaprevir-based PI-PR, respectively. AE-related burden may increase with PI-PR. Future studies should incorporate AE-related economic and HRQoL outcomes to comprehensively assess costs/benefits.
Topics: Antiviral Agents; Drug Therapy, Combination; Health Care Costs; Hepatitis C; Humans; Interferons; Protease Inhibitors; Quality of Life; Ribavirin
PubMed: 22812557
DOI: 10.1586/erp.12.10 -
Biochemistry. Biokhimiia Sep 2023Entomopathogenic bacteria of the genus Photorhabdus secrete protease S (PrtS), which is considered a virulence factor. We found that in the Photorhabdus genomes,...
Entomopathogenic bacteria of the genus Photorhabdus secrete protease S (PrtS), which is considered a virulence factor. We found that in the Photorhabdus genomes, immediately after the prtS genes, there are genes that encode small hypothetical proteins homologous to emfourin, a recently discovered protein inhibitor of metalloproteases. The gene of emfourin-like inhibitor from Photorhabdus laumondii subsp. laumondii TT01 was cloned and expressed in Escherichia coli cells. The recombinant protein, named photorin (Phin), was purified by metal-chelate affinity and gel permeation chromatography and characterized. It has been established that Phin is a monomer and inhibits activity of protealysin and thermolysin, which, similar to PrtS, belong to the M4 peptidase family. Inhibition constants were 1.0 ± 0.3 and 10 ± 2 µM, respectively. It was also demonstrated that Phin is able to suppress proteolytic activity of P. laumondii culture fluid (half-maximal inhibition concentration 3.9 ± 0.3 nM). Polyclonal antibodies to Phin were obtained, and it was shown by immunoblotting that P. laumondii cells produce Phin. Thus, the prtS genes in entomopathogenic bacteria of the genus Photorhabdus are colocalized with the genes of emfourin-like inhibitors, which probably regulate activity of the enzyme during infection. Strict regulation of the activity of proteolytic enzymes is essential for functioning of all living systems. At the same time, the principles of regulation of protease activity by protein inhibitors remain poorly understood. Bacterial protease-inhibitor pairs, such as the PrtS and Phin pair, are promising models for in vivo studies of these principles. Bacteria of the genus Photorhabdus have a complex life cycle with multiple hosts, being both nematode symbionts and powerful insect pathogens. This provides a unique opportunity to use the PrtS and Phin pair as a model for studying the principles of protease activity regulation by proteinaceous inhibitors in the context of bacterial interactions with different types of hosts.
Topics: Animals; Photorhabdus; Protease Inhibitors; Insecta; Anti-Infective Agents; Antiviral Agents
PubMed: 37770402
DOI: 10.1134/S0006297923090158 -
Parasites & Vectors Apr 2017Aspartyl protease inhibitor (API) was thought to protect intestinal parasitic nematodes from their hostile proteolytic environment. Studies on Ostertagia ostertagi,...
BACKGROUND
Aspartyl protease inhibitor (API) was thought to protect intestinal parasitic nematodes from their hostile proteolytic environment. Studies on Ostertagia ostertagi, Ascaris suum and Brugia malayi indicated that aspins might play roles in nematode infection. In a recent study, proteins differentially expressed between free-living third-stage larvae (L3) and activated L3 (xL3) of Haemonchus contortus were identified by 2D-DIGE. API was found downregulated in xL3 when compared with L3. However, there was no report about the functions of H. contortus API in the parasite-host interaction. In this study, the gene encoding API from H. contortus was cloned, expressed, and part of its biological characteristics were studied.
RESULTS
A DNA fragment of 681 bp was amplified by RT-PCR. Ninety one percent of the amino acid sequence was similar with that for aspin from O. ostertagi. The recombinant API protein was fusion-expressed with a molecular weight of 48 × 10. Results of Western blot showed that the recombinant API could be recognized by serum from goat infected with H. contortus. It was found that API was localized exclusively in the subcutaneous tissue and epithelial cells of the gastrointestinal tract in adult H. contortus. qRT-PCR suggested that the API gene was differentially transcribed in different life-cycle stages, with the lowest level in female adults and the highest in free-living L3 larvae. Enzyme inhibition assay indicated that the recombinant API can inhibit the activity of pepsin significantly, and the optimal reaction pH and temperature were 4.0 and 37-50 °C respectively. In vitro study showed that the recombinant API could induce goat PBMCs to express IFN-γ, IL-4 and IL-10.
CONCLUSIONS
A new aspartyl protease inhibitor was cloned from H. contortus and its characteristics were studied for the first time. The results indicate that API may regulate the immune response of the host and play roles in the infection.
Topics: Animals; Aspartic Acid Proteases; Cloning, Molecular; Cytokines; Female; Goats; Haemonchiasis; Haemonchus; Host-Parasite Interactions; Leukocytes, Mononuclear; Life Cycle Stages; Male; Pepsin A; Protease Inhibitors; Real-Time Polymerase Chain Reaction; Recombinant Proteins
PubMed: 28420411
DOI: 10.1186/s13071-017-2137-1 -
Archiv Der Pharmazie Apr 2023Cyclization of small molecules is a widely applied strategy in drug design for ligand optimization to improve affinity, as it eliminates the putative need for structural...
Cyclization of small molecules is a widely applied strategy in drug design for ligand optimization to improve affinity, as it eliminates the putative need for structural preorganization of the ligand before binding, or to improve pharmacokinetic properties. In this work, we provide a deeper insight into the binding thermodynamics of a macrocyclic Zika virus NS2B/NS3 protease inhibitor and its linear analogs. Characterization of the thermodynamic binding profiles by isothermal titration calorimetry experiments revealed an unfavorable entropy of the macrocycle compared to the open linear reference ligands. Molecular dynamic simulations and X-ray crystal structure analysis indicated only minor benefits from macrocyclization to fixate a favorable conformation, while linear ligands retained some flexibility even in the protein-bound complex structure, possibly explaining the initially surprising effect of a higher entropic penalty for the macrocyclic ligand.
Topics: Humans; Zika Virus; Ligands; Viral Nonstructural Proteins; Protein Conformation; Structure-Activity Relationship; Serine Endopeptidases; Thermodynamics; Protease Inhibitors; Zika Virus Infection
PubMed: 36480352
DOI: 10.1002/ardp.202200518 -
European Journal of Trauma and... Jun 2022Trauma and hemorrhagic shock (T/HS) is a major cause of morbidity and mortality. Existing treatment options are largely limited to source control and fluid and blood...
PURPOSE
Trauma and hemorrhagic shock (T/HS) is a major cause of morbidity and mortality. Existing treatment options are largely limited to source control and fluid and blood repletion. Previously, we have shown that enteral protease inhibition improves outcomes in experimental models of T/HS by protecting the gut from malperfusion and ischemia. However, enteral protease inhibition was achieved invasively, by laparotomy and direct injection of tranexamic acid (TXA) into the small intestine. In this study, we tested a minimally invasive method of enteral protease inhibitor infusion in experimental T/HS that can be readily adapted for clinical use.
METHODS
Wistar rats were exsanguinated to a mean arterial blood pressure (MABP) of 40 mmHg, with laparotomy to induce trauma. Hypovolemia was maintained for 120 min and was followed by reperfusion of shed blood. Animals were monitored for an additional 120 min. A modified orogastric multi-lumen tube was developed to enable rapid enteral infusion of a protease inhibitor solution while simultaneously mitigating risk of reflux aspiration into the airways. The catheter was used to deliver TXA (T/HS + TXA) or vehicle (T/HS) continuously into the proximal small intestine, starting 20 min into the ischemic period.
RESULTS
Rats treated with enteral protease inhibition (T/HS + TXA) displayed improved outcomes compared to control animals (T/HS), including significantly improved MABP (p = 0.022) and lactate (p = 0.044). Mass spectrometry-based analysis of the plasma peptidome after T/HS indicated mitigation of systemic proteolysis in T/HS + TXA.
CONCLUSION
Minimally invasive, continuous enteral protease inhibitor delivery improves outcomes in T/HS and is readily translatable to the clinical arena.
Topics: Animals; Disease Models, Animal; Humans; Intestine, Small; Ischemia; Protease Inhibitors; Rats; Rats, Wistar; Shock, Hemorrhagic; Tranexamic Acid
PubMed: 33483765
DOI: 10.1007/s00068-020-01591-y -
Biological Chemistry Hoppe-Seyler May 1988Human mucous secretions contain a proteinase inhibitor which is produced locally and inhibits, besides trypsin and chymotrypsin, granulocytic elastase and cathepsin G as... (Review)
Review
Human mucous secretions contain a proteinase inhibitor which is produced locally and inhibits, besides trypsin and chymotrypsin, granulocytic elastase and cathepsin G as well as mast cell chymase and tryptase. The various inhibitors isolated from different sources (bronchial mucus, parotid secretion, seminal plasma, cervical mucus, etc.) and named accordingly (bronchial mucus inhibitor, BMI; human seminal inhibitor I, HUSI-I; cervical mucus inhibitors, CUSI; antileukoprotease, ALP; secretory leukocyte protease inhibitor, SLPI) proved to be identical or derived from a mature inhibitory protein encoded by a single gene of the human genom. Therefore, this inhibitor should be named mucus proteinase inhibitor, MPI. Such a neutral terminus would help to avoid misleading interpretations of already published data and also of the biological role of this inhibitory protein because the MPI may serve several and different physiological functions.
Topics: Humans; Protease Inhibitors; Proteinase Inhibitory Proteins, Secretory; Proteins; Secretory Leukocyte Peptidase Inhibitor; Serine Proteinase Inhibitors
PubMed: 3060147
DOI: No ID Found -
Peptides Dec 2009Plant aspartic proteases are of recent origin with their physiological significance in crucial processes emerging. Reports on the significance of aspartic protease...
Plant aspartic proteases are of recent origin with their physiological significance in crucial processes emerging. Reports on the significance of aspartic protease inhibitors and their endogenous proteases in seeds of plants are scanty. This paper reports the purification of an aspartic protease inhibitor from the seeds of Vigna radiata, its control of the endogenous aspartic protease and their subsequent role in the early germination events. The role of the aspartic protease inhibitor and the enzyme in initial stages of germination of V. radiata has been tracked by differential timed expression and germination assays. The expression pattern revealed maximum expression of the inhibitor in the dormant seeds while the enzyme was predominant in the germinating seeds. Their expression patterns and interactions indicate their significance in initiation of germination. The expression of other classes of proteases was monitored during germination and a model predicting the events occurring during proteolysis of the storage protein in germination is hypothesized. The inhibitor was a linear, hydrophobic, pH stable and thermostable peptide with molecular weight of 1660 Da. The purified inhibitor showed a pI of 4.36 with the sequence as AEIYN KDGNK LDLYG. The inhibitor was found to be stable in a broad range of pH from 2 to 10 with an optimum of 3.0. The half-life of VrAPI at 100 degrees C was 30 min whereas the maximum activity was observed at 37 degrees C. The initial kinetic analysis of the inhibitor against the endogenous protease showed an IC(50) value of 11 nM while the value of the inhibition rate constant K(i) was 34 x 10(-9)M.
Topics: Aspartic Acid Endopeptidases; Fabaceae; Gene Expression Regulation, Plant; Germination; Kinetics; Peptide Hydrolases; Peptides; Plant Proteins; Protease Inhibitors; Seeds
PubMed: 19770015
DOI: 10.1016/j.peptides.2009.08.024