1
|
Kumar A, Balbach J. Inactivation of parathyroid hormone: perspectives of drug discovery to combating hyperparathyroidism. Curr Mol Pharmacol 2021; 15:292-305. [PMID: 33573587 DOI: 10.2174/1874467214666210126112839] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 11/09/2020] [Accepted: 11/10/2020] [Indexed: 11/22/2022]
Abstract
Hormonal coordination is tightly regulated within the human body and thus regulates human physiology. The parathyroid hormone (PTH), a member of the endocrine system, regulates the calcium and phosphate level within the human body. Under non-physiological conditions, PTH levels get upregulated (hyperparathyroidism) or downregulated (hypoparathyroidism) due to external or internal factors. In the case of hyperparathyroidism, elevated PTH stimulates cellular receptors present in the bones, kidneys, and intestines to increase the blood calcium level, leading to calcium deposition. This eventually causes various symptoms including kidney stones. Currently, there is no known medication that directly targets PTH in order to suppress its function. Therefore, it is of great interest to find novel small molecules or any other means that can modulate PTH function. The molecular signaling of PTH starts by binding of its N-terminus to the G-protein coupled PTH1/2 receptor. Therefore, any intervention that affects the N-terminus of PTH could be a lead candidate for treating hyperparathyroidism. As a proof-of-concept, there are various possibilities to inhibit molecular PTH function by (i) a small molecule, (ii) N-terminal PTH phosphorylation, (iii) fibril formation and (iv) residue-specific mutations. These modifications put PTH into an inactive state, which will be discussed in detail in this review article. We anticipate that exploring small molecules or other means that affect the N-terminus of PTH could be lead candidates in combating hyperparathyroidism.
Collapse
Affiliation(s)
- Amit Kumar
- Department of Life Sciences, Faculty of Natural Sciences, Imperial College of Science, Technology and Medicine London, South Kensington, London SW7 2BU. United Kingdom
| | - Jochen Balbach
- Institute of Physics, Biophysics, Martin-Luther-University Halle- Wittenberg. Germany
| |
Collapse
|
2
|
Giri B, Saini T, Kumbhakar S, Selvan K K, Muley A, Misra A, Maji S. Near-IR light-induced photorelease of nitric oxide (NO) on ruthenium nitrosyl complexes: formation, reactivity, and biological effects. Dalton Trans 2020; 49:10772-10785. [PMID: 32706352 DOI: 10.1039/d0dt01788d] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Polypyridyl backbone nitrosyl complexes of ruthenium with the molecular framework [RuII(antpy)(bpy)NO+/˙]n+ [4](PF6)3 (n = 3), [4](PF6)2 (n = 2), where antpy = 4'-(anthracene-9-yl)-2,2':6',2''-terpyridine and bpy = 2,2'-bipyridine, were synthesized via a stepwise synthetic route from the chloro precursor [RuII(antpy)(bpy)(Cl)](PF6) [1](PF6) and [RuII(antpy)(bpy)(CH3CN)](PF6)2 [2](PF6)2 and [RuII(antpy)(bpy)(NO2)](PF6) [3](PF6). After column chromatographic purification, all the synthesized complexes were fully characterized using different spectroscopic and analytical techniques including mass spectroscopy, 1H NMR, FT-IR and UV-vis spectrophotometry. The Ru-NO stretching frequency of [4](PF6)3 was observed at 1941 cm-1, which suggests moderately strong Ru-NO bonding. A massive shift in the νNO frequency occurred at Δν = 329 cm-1 (solid) upon reducing [4](PF6)3 to [4](PF6)2. To understand the molecular integrity of the complexes, the structure of [3](PF6) was successfully determined by X-ray crystallography. The redox properties of [4](PF6)3 were thoroughly investigated together with the other precursor complexes. The rate constants for the first-order photo-release of NO from [4](PF6)3 and [4](PF6)2 were determined to be 8.01 × 10-3 min-1 (t1/2 ∼ 86 min) and 3.27 × 10-2 min-1 (t1/2 ∼ 21 min), respectively, when exposed to a 200 W Xenon light. Additionally, the photo-cleavage of Ru-NO occurred within ∼2 h when [4](PF6)3 was irradiated with an IR light source (>700 nm) at room temperature. The first-order rate constant of 9.4 × 10-3 min-1 (t1/2 ∼ 73 min) shows the efficacy of the system and its capability to release NO in the photo-therapeutic window. The released NO triggered by light was trapped by reduced myoglobin, a biologically relevant target protein. The one-electron reduction of [4](PF6)3 to [4](PF6)2 was systematically carried out chemically (hydrazine hydrate), electrochemically and biologically. In the biological reduction, it was found that the reduction is much slower with double-stranded DNA compared to a single-stranded oligonucleotide (CAAGGCCAACCGCGAGAAGATGAC). Moreover, [4](PF6)3 exhibited significant photo-toxicity to the VCaP prostate cancer cell line upon irradiation with a visible light source (IC50 ∼ 8.97 μM).
Collapse
Affiliation(s)
- Bishnubasu Giri
- Department of Chemistry, Indian Institute of Technology, Hyderabad, Kandi, Sangareddy 502285, Telangana, India.
| | - Taruna Saini
- Department of Biotechnology, Indian Institute of Technology, Hyderabad, Kandi, Sangareddy 502285, Telangana, India
| | - Sadananda Kumbhakar
- Department of Chemistry, Indian Institute of Technology, Hyderabad, Kandi, Sangareddy 502285, Telangana, India.
| | - Kalai Selvan K
- Department of Chemistry, Indian Institute of Technology, Hyderabad, Kandi, Sangareddy 502285, Telangana, India.
| | - Arabinda Muley
- Department of Chemistry, Indian Institute of Technology, Hyderabad, Kandi, Sangareddy 502285, Telangana, India.
| | - Ashish Misra
- Department of Biotechnology, Indian Institute of Technology, Hyderabad, Kandi, Sangareddy 502285, Telangana, India
| | - Somnath Maji
- Department of Chemistry, Indian Institute of Technology, Hyderabad, Kandi, Sangareddy 502285, Telangana, India.
| |
Collapse
|
3
|
Velugula K, Kumar A, Chinta JP. Nuclease and anticancer activity of antioxidant conjugated terpyridine metal complexes. Inorganica Chim Acta 2020. [DOI: 10.1016/j.ica.2020.119596] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
|
4
|
In-Cell NMR: Analysis of Protein-Small Molecule Interactions, Metabolic Processes, and Protein Phosphorylation. Int J Mol Sci 2019; 20:ijms20020378. [PMID: 30658393 PMCID: PMC6359726 DOI: 10.3390/ijms20020378] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 01/11/2019] [Accepted: 01/13/2019] [Indexed: 01/31/2023] Open
Abstract
Nuclear magnetic resonance (NMR) spectroscopy enables the non-invasive observation of biochemical processes, in living cells, at comparably high spectral and temporal resolution. Preferably, means of increasing the detection limit of this powerful analytical method need to be applied when observing cellular processes under physiological conditions, due to the low sensitivity inherent to the technique. In this review, a brief introduction to in-cell NMR, protein–small molecule interactions, posttranslational phosphorylation, and hyperpolarization NMR methods, used for the study of metabolites in cellulo, are presented. Recent examples of method development in all three fields are conceptually highlighted, and an outlook into future perspectives of this emerging area of NMR research is given.
Collapse
|
5
|
Kumar A, Kuhn LT, Balbach J. A Cu 2+ complex induces the aggregation of human papillomavirus oncoprotein E6 and stabilizes p53. FEBS J 2018; 285:3013-3025. [PMID: 29931810 DOI: 10.1111/febs.14591] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Revised: 05/14/2018] [Accepted: 06/20/2018] [Indexed: 12/13/2022]
Abstract
Papillomavirus oncoprotein E6 is a critical factor in the modulation of cervical cancer in humans. At the molecular level, formation of the E6-E6AP-p53 ternary complex, which directs p53's degradation, is the key instigator of cancer transforming properties. Herein, a Cu2+ anthracenyl-terpyridine complex is described which specifically induces the aggregation of E6 in vitro and in cultured cells. For a hijacking mechanism, both E6 and E6AP are required for p53 ubiquitination and degradation. The Cu2+ complex interacts with E6 at the E6AP and p53 binding sites. We show that E6 function is suppressed by aggregation, rendering it incapable of hijacking p53 and thus increasing its cellular level. Therapeutic treatments of cervical cancer are currently unavailable to infected individuals. We anticipate that this Cu2+ complex might open up a new therapeutic avenue for the design and development of new chemical entities for the diagnosis and treatment of HPV-induced cancers.
Collapse
Affiliation(s)
- Amit Kumar
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, University of Leeds, UK.,Institute of Physics, Biophysics, Martin-Luther-University Halle-Wittenberg, Germany.,Institute of Technical Biochemistry e.V., Martin-Luther-University Halle-Wittenberg, Germany
| | - Lars T Kuhn
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, University of Leeds, UK
| | - Jochen Balbach
- Institute of Physics, Biophysics, Martin-Luther-University Halle-Wittenberg, Germany.,Institute of Technical Biochemistry e.V., Martin-Luther-University Halle-Wittenberg, Germany
| |
Collapse
|