BINDING OF 17-SUBSTITUTED 16-NITRILE 16,17-SECOESTRANE COMPOUNDS TO ESTROGEN RECEPTORS – „IN VITRO“ AND „IN SILICO“ STUDY

2021 ◽  
Author(s):  
Suzana S. Jovanović-Šanta ◽  
◽  
Esma Isenović ◽  
Julijana A. Petrović ◽  
Yaraslau U. Dzichenka
Keyword(s):  
Amino Acids ◽  
Estrogen Receptors ◽  
Nuclear Translocation ◽  
Binding Mode ◽  
High Rate ◽  
Dynamics Simulation ◽  
Breast Cancers ◽  
Number Of Binding Sites ◽  
Almost All

About 75% of breast cancers express estrogen receptors (ERs), which is a good base for an efficient endocrine therapy. This gives the opportunity for the treatment of patients with antiestrogens, compounds that bind to the ERs and thus compete to estradiol (E2), preventing its action in progression of estrogen-depending cancers. Here we present results of testing the effect of the modified steroids, namely 17-substituted 16-nitrile 16,17-secoestrane compounds on the E2-ER complex forming, its stability, nuclear translocation and binding to DNA. Almost all compounds in moderate to high rate induced lower forming of this complex, destabilizing it – they increased Kd of this complex and decreased number of binding sites. Complex formed in the presence of some test secosteroids could pass to the nucleus, while other compounds inhibited translocation. In the presence of some compounds binding of the formed complex E2-ER to DNA was noticed. Docking followed molecular dynamics simulation was performed to reveal binding mode of E2 to ER in the presence of test secosteroids. Amino acids important for binding process and complex stabilization were detected. Analysis of the simulation data allowed identifying key amino acids and type of binding of the secoestrane compounds, important for high affinity binding of the steroidal compounds.

Prospects for stable analogues of phosphohistidine

2013 ◽  
Vol 41 (4) ◽  
pp. 1072-1077 ◽  
Author(s):  
Tom E. McAllister ◽  
Jeffrey J. Hollins ◽  
Michael E. Webb
Keyword(s):  
Amino Acids ◽  
Chemical Synthesis ◽  
Short Review ◽  
Signalling Pathways ◽  
Post Translational Modification ◽  
Almost All

Phosphorylation is a ubiquitous protein post-translational modification, and the importance of phosphorylation of serine, threonine and tyrosine is well established. What is lesser known is that almost all heteroatom-containing amino acids can be phosphorylated and, among these, histidine, aspartate and cysteine have well established roles in bacterial signalling pathways. The first of these, phosphohistidine, is the most unusual in that it is labile under many conditions used to study proteins in vitro and can exist as two different isomers. In the present short review, we highlight the chemical challenges that this modification presents and the manner in which chemical synthesis has been used to identify and mimic the modification in proteins.

scholarly journals The potential terminase subunit of human cytomegalovirus, pUL56, is translocated into the nucleus by its own nuclear localization signal and interacts with importin α

2000 ◽  
Vol 81 (9) ◽  
pp. 2231-2244 ◽  
Author(s):  
Kyra Giesen ◽  
Klaus Radsak ◽  
Elke Bogner
Keyword(s):  
Amino Acids ◽  
Human Cytomegalovirus ◽  
Nuclear Localization ◽  
Nuclear Localization Signal ◽  
Nuclear Translocation ◽  
Reporter Protein ◽  
Importin Α ◽  
Localization Signal ◽  
Carboxy Terminal

Human cytomegalovirus (HCMV) DNA-binding protein pUL56 is thought to be involved in the cleavage/packaging process of viral DNA and therefore needs to be transported into the nucleus. By using indirect immunofluorescence analysis, HCMV pUL56 (p130) was found to be localized predominantly in the nucleus of infected cells. Solitary expression of wild-type as well as epitope-tagged pUL56 also resulted in nuclear distribution after transfection, suggesting the presence of an endogenous nuclear localization signal (NLS). Deletion of a carboxy-terminal stretch of basic amino acids (aa 816–827) prevented nuclear translocation, indicating that the sequence RRVRATRKRPRR of HCMV pUL56 mediates nuclear targetting. The signal character of the NLS sequence was demonstrated by successful transfer of the NLS to a reporter protein chimera. Furthermore, sequential substitutions of pairs of amino acids by alanine in the context of the reporter protein as well as substitutions within the full-length pUL56 sequence indicated that residues at positions 7 and 8 of the NLS (R and K at positions 822 and 823 of pUL56) were essential for nuclear translocation. In order to identify the transport machinery involved, the potential of pUL56 to bind importin α (hSRP1α) was examined. Clear evidence of a direct interaction of a carboxy-terminal portion as well as the NLS of pUL56 with hSRP1α was provided by in vitro binding assays. In view of these findings, it is suggested that nuclear translocation of HCMV pUL56 is mediated by the importin-dependent pathway.

scholarly journals The repurposed drugs suramin and quinacrine inhibit cooperatively in vitro SARS-CoV-2 3CLpro

2020 ◽  
Author(s):  
Raphael J. Eberle ◽  
Danilo S. Olivier ◽  
Marcos S. Amaral ◽  
Dieter Willbold ◽  
Raghuvir K. Arni ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Amino Acids ◽  
Drug Repositioning ◽  
Binding Mode ◽  
Main Protease ◽  
Repurposed Drugs ◽  
Inhibitory Potential ◽  
Dynamics Simulations ◽  
Synergistic Drug Combinations

AbstractSince the first report of a new pneumonia disease in December 2019 (Wuhan, China) up to now WHO reported more than 50 million confirmed cases and more than one million losses, globally. The causative agent of COVID-19 (SARS-CoV-2) has spread worldwide resulting in a pandemic of unprecedented magnitude. To date, no clinically safe drug or vaccine is available and the development of molecules to combat SARS-CoV-2 infections is imminent. A well-known strategy to identify molecules with inhibitory potential against SARS-CoV-2 proteins is the repurposing of clinically developed drugs, e.g., anti-parasitic drugs. The results described in this study demonstrate the inhibitory potential of quinacrine and suramin against SARS-CoV-2 main protease (3CLpro). Quinacrine and suramin molecules present a competitive and non-competitive mode of inhibition, respectively, with IC50 and KD values in low μM range. Using docking and molecular dynamics simulations we identified a possible binding mode and the amino acids involved in these interactions. Our results suggested that suramin in combination with quinacrine showed promising synergistic efficacy to inhibit SARS-CoV-2 3CLpro. The identification of effective, synergistic drug combinations could lead to the design of better treatments for the COVID-19 disease. Drug repositioning offers hope to the SARS-CoV-2 control.

UTILIZATION OF UNIFORMLY LABELLED 14C-GLUCOSE IN THE PINEAL BODY OF GOATS

1961 ◽  
Vol 38 (3) ◽  
pp. 353-360 ◽  
Author(s):  
Bo Hellman ◽  
Stig Larsson
Keyword(s):  
Amino Acids ◽  
High Rate ◽  
Pineal Body ◽  
Chromatographic Technique ◽  
Microscopical Examination ◽  
Age Group ◽  
Wet Weight ◽  
Parenchymal Cells ◽  
Very High

ABSTRACT The in vitro utilization of uniformly 14C-labelled glucose was studied in the pineal body of goats by using a quantitative application of the radio paper-chromatographic technique. The O2 consumption as well as the formation of CO2 and lactic acid from glucose in the incubation medium was comparatively very high in young goats and decreased gradually with increasing age. The same was true for the formation of labelled amino acids. Thus, there were no measurable amounts of radioactive amino acids in goats older than 6 years, while in the animals 1–3 months old no less than 11.7 μg glucose was converted into amino acids per 25 mg wet weight of the pineal body Glutamic acid and alanine were found in the highest amounts among the different amino acids formed from glucose in the youngest age group. There were also appreciable amounts of arginine, glutamine, δ-aminobutyric acid and aspartic acid. Microscopical examination revealed that not only progressive degenerative changes but also a markedly reduced number of parenchymal cells per unit volume, might account for the diminished glucose metabolism found in the pineal body of adult goats. The metabolic findings, especially the very high rate of formation of amino acids from glucose in the youngest animals, are discussed in the light of the result of recent investigations, which suggest secretion of a protein hormone from the non-adult pineal body.

scholarly journals REGULATION OF PROTEIN SYNTHESIS IN THE VENOM GLAND OF VIPERID SNAKES

1973 ◽  
Vol 56 (1) ◽  
pp. 177-190 ◽  
Author(s):  
U. Oron ◽  
A. Bdolah
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Morphological Changes ◽  
Venom Gland ◽  
High Rate ◽  
Secretory Cells ◽  
Intracellular Level ◽  
Secretory Cycle ◽  
Venom Proteins

Morphological changes in the venom gland of V. ammodytes were studied after the removal of the venom from the gland lumina (milking) It was found that the height of the secretory cells was changed during the secretory cycle. The patterns of the rough endoplasmic reticulum and of the Golgi complex were changed as well Milking induced an increased incorporation of [14C]amino acids into total and venom proteins In V ammodytes, during the first day after milking, 25% of the total counts in protein were precipitable by anti-venom serum, while at 8 days, 80% of the proteins synthesized were venom proteins At this stage, the incorporation was 10- and 20-fold that of unmilked glands for total and venom proteins, respectively. Venom was accumulated (secreted) in the gland lumina of V. ammodytes at a relatively high rate up to 2 wk after milking and leveled off afterwards. Intact glands and gland slices of V ammodytes and V palaestinae, taken from snakes a few days after milking, incorporated [14C]amino acids into proteins in vitro at a rate higher than that of unmilked glands. The activity of two exportable enzymes (phosphodiesterase and benzoyl arginyl ethyl esterase) was assayed in gland homogenates of V. ammodytes. It was found that 2–3 wk after milking, the intracellular level of these enzymes was up to 2-fold that of unmilked glands.

scholarly journals An immunoinformatics study: designing multivalent T-cell epitope vaccine against canine circovirus

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Pankaj Jain ◽  
Amit Joshi ◽  
Nahid Akhtar ◽  
Sunil Krishnan ◽  
Vikas Kaushik
Keyword(s):  
Molecular Dynamics ◽  
Amino Acids ◽  
Molecular Docking ◽  
In Silico ◽  
Cell Epitope ◽  
Cost Effective ◽  
Dynamics Simulation ◽  
Cloning And Expression

Abstract Background Canine circovirus is a deadly pathogen of dogs and causes vasculitis and hemorrhagic enteritis. It causes lethal gastroenteritis in pigs, fox, and dogs. Canine circovirus genome contains two main (and opposite) transcription units which encode two open reading frames (ORFs), a replicase-associated protein (Rep) and the capsid (Cap) protein. The replicase protein and capsid protein consist of 303 amino acids and 270 amino acids respectively. Several immuno-informatics methods such as epitope screening, molecular docking, and molecular-dynamics simulations were used to craft peptide-based vaccine construct against canine circovirus. Results The vaccine construct was designed by joining the selected epitopes with adjuvants by suitable linker. The cloning and expression of the vaccine construct was also performed using in silico methods. Screening of epitopes was conducted by NetMHC server that uses ANN (Artificial neural networking) algorithm. These methods are fast and cost-effective for screening epitopes that can interact with dog leukocyte antigens (DLA) and initiate an immune response. Overall, 5 epitopes, YQHLPPFRF, YIRAKWINW, ALYRRLTLI, HLQGFVNLK, and GTMNFVARR, were selected and used to design a vaccine construct. The molecular docking and molecular dynamics simulation studies show that these epitopes can bind with DLA molecules with stability. The codon adaptation and in silico cloning studies show that the vaccine can be expressed by Escherichia coli K12 strain. Conclusion The results suggest that the vaccine construct can be useful in preventing the dogs from canine circovirus infections. However, the results need further validation by performing other in vitro and in vivo experiments.

scholarly journals Recent Advances in Enhancing the Therapeutic Index of PARP Inhibitors in Breast Cancer

Cancers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 4132
Author(s):  
Camille Franchet ◽  
Jean-Sébastien Hoffmann ◽  
Florence Dalenc
Keyword(s):  
Treatment Strategies ◽  
Therapeutic Index ◽  
Parp Inhibitors ◽  
Resistance Mechanisms ◽  
High Rate ◽  
Parp Inhibition ◽  
Breast Cancers ◽  
Synthetic Lethal ◽  
Novel Treatment Strategies

As poly-(ADP)-ribose polymerase (PARP) inhibition is synthetic lethal with the deficiency of DNA double-strand (DSB) break repair by homologous recombination (HR), PARP inhibitors (PARPi) are currently used to treat breast cancers with mutated BRCA1/2 HR factors. Unfortunately, the increasingly high rate of PARPi resistance in clinical practice has dented initial hopes. Multiple resistance mechanisms and acquired vulnerabilities revealed in vitro might explain this setback. We describe the mechanisms and vulnerabilities involved, including newly identified modes of regulation of DSB repair that are now being tested in large cohorts of patients and discuss how they could lead to novel treatment strategies to improve the therapeutic index of PARPi.

scholarly journals Histochemical analyses of steroid hormone receptors in breast and prostatic carcinoma.

1980 ◽  
Vol 28 (8) ◽  
pp. 799-810 ◽  
Author(s):  
L P Pertschuk ◽  
E H Tobin ◽  
P Tanapat ◽  
E Gaetjens ◽  
A C Carter ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Prostatic Carcinoma ◽  
Hormone Receptors ◽  
Nuclear Translocation ◽  
Stage Iv ◽  
Poor Response ◽  
Response To Therapy ◽  
Steroid Hormone Receptors ◽  
Breast Cancers

Histochemical analyses estrogen (ER) and progesterone (PgR) receptors in breast cancer were statistically correlated with results of dextran-coated charcoal (DDC) and sucrose gradient assays. Correlated for ER was 91% of 363 cases, and for PgR 88% of 255 specimens. Breast cancer ER/PgR positivity by histochemistry correlated with a favorable clinical response to endocrine therapies in 72% of 25 cases, while ER/PgR negativity correlated with a lack of response in 96% of 22 cases with Stage IV disease. Nuclear ER/PgR correlated with a poor response to therapy in 8 of 12 patients. An in vitro technique to detect nuclear translocation of ER revealed two groups of ER positive cases, with 11 of 17 exhibiting translocation and 6 not displaying translocation. In prostatic carcinoma, 72% of 65 men were positive for ER and/or androgen receptor. Comparison of specimens obtained without and with electrocautery revealed a preponderance of nuclear binding in the latter, suggesting heat-induced nuclear translocation of receptor. coumestrol, a naturally fluorescent, entirely unaltered estrogen was also used for histochemical detection of ER. Results correlated with ER by DCC in 87% of 61 breast cancers. Coumestrol was additionally used to visually observe receptor and nuclear translocation of ER in intact whole cells in culture.

scholarly journals Ostrich Involvement in the Selection of H5N1 Influenza Virus Possessing Mammalian-Type Amino Acids in the PB2 Protein

2009 ◽  
Vol 83 (24) ◽  
pp. 13015-13018 ◽  
Author(s):  
Kyoko Shinya ◽  
Akiko Makino ◽  
Makoto Ozawa ◽  
Jin Hyun Kim ◽  
Yuko Sakai-Tagawa ◽  
...  
Keyword(s):  
Amino Acids ◽  
Avian Influenza ◽  
Mammalian Cells ◽  
Influenza A ◽  
Influenza Viruses ◽  
High Rate ◽  
Qinghai Lake ◽  
H5n1 Influenza

ABSTRACT Amino acids at positions 627 and 701 in the PB2 protein (PB2-627 and PB2-701, respectively) of avian influenza A viruses affect virus replication in some mammalian cells. Highly pathogenic H5N1 influenza viruses possessing mammalian-type PB2-627 were detected during the Qinghai Lake outbreak in 2005 and spread to Europe and Africa. Via a database search, we found a high rate of viral isolates from Ratitae, including ostrich, possessing mammalian-type PB2-627 or -701. Here, we report that H5N1 avian influenza viruses possessing mammalian-type amino acids in PB2-627 or -701 are selected during replication in ostrich cells in vitro and in vivo.

Synthesis and Molecular Simulation Studies of Mandelic Acid Peptidomimetic Derivatives as Aminopeptidase N Inhibitors

2020 ◽  
Vol 16 ◽  
Author(s):  
Jiawei Chen ◽  
Qiaoli Lv ◽  
Guogang Tu
Keyword(s):  
Molecular Simulation ◽  
Mandelic Acid ◽  
Critical Role ◽  
Binding Mode ◽  
Biological Evaluation ◽  
Binding Energies ◽  
Aminopeptidase N ◽  
Dynamics Simulation ◽  
Inhibitory Activities

Background: The aminopeptidase N (APN) over-expressed in tumor cells plays a critical role in angiogenesis which makes the development of APN inhibitors an attractive strategy for cancer research. Aims and Objectives: It is clinically significant to develop potential APN inhibitors for cancer treatment. Reported here are the design, synthesis, biological evaluation and molecular simulation of mandelic acid peptidomimetic derivatives as APN inhibitors. Materials and Methods: Analysis of the binding mode of bestatin to APN lead to the design and synthesis of mandelic acid peptidomimetic derivatives. APN inhibitory activities in vitro were evaluated by spectrophotometric method. The binding mode of the target compounds with the APN binding site was studied relying on docking studies, molecular dynamics simulation experiments and binding energies calculation. Results: The structures of target compounds were confirmed by IR, 1H-NMR and MS. All compounds exhibited different range of inhibitory ability with IC50 values lying in micromolar level. The compound 9m was found to be most potent as compared to other target derivatives. Molecular simulation revealed that ligand coordinating with the catalytic zinc ion is very important for inhibitory activities. Conclusion: The compound 9m might represent a promising scaffold for the further development of novel anti-cancer drugs.

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