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Kusza DA, Venter GA, Mabunda M, Biwi J, Samanta SK, Klinck JD, Singh SV, Hunter R, Kaschula CH. Finding the Ajoene Sweet-Spot: Structure-Activity Relations that Govern its Blood Stability and Cancer Cytotoxicity. ChemMedChem 2024; 19:e202400087. [PMID: 38532643 DOI: 10.1002/cmdc.202400087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Revised: 03/15/2024] [Accepted: 03/19/2024] [Indexed: 03/28/2024]
Abstract
Ajoene is an organosulfur compound found in crushed garlic that exerts its anti-cancer activity by S-thiolating cysteine residues on proteins. Its development is hampered due to limited bioavailability, so in this study, we synthesised analogues of ajoene to probe the significance of the ajoene vinyl disulfide/sulfoxide core with respect to cytotoxicity and blood stability. Polar side groups were also incorporated to improve aqueous solubility. It was found that derivatives containing a vinyl disulfide functional group (4-7, as in ajoene), were more cytotoxic compared to analogues in which the double bond was removed, although the latter showed superior blood stability. It was also found that the allyl-S sulfur of the disulfide was more electrophilic to S-thiolysis based on the global electrophilicity index (ω) and the condensed electrophilic Fukui functionf k + ${{ f}_{\rm{k}}^{\rm{ + }} }$ . S-Thiolysis was found to be exergonic for the vinyl disulfides based on entropy and enthalpy computations with a deprotonated thiolate. Derivatisation to the dihydro (10, 12) and deoxydihydroajoenes (9, 11) produced analogues that were slightly less potent but with greatly improved blood stability. Taken together, the deoxydihydroajoenes present themselves as good candidates for further therapeutic development.
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Affiliation(s)
- Daniel A Kusza
- Department of Chemistry, University of Cape Town, Rondebosch, Cape Town, 7701, South Africa
| | - Gerhard A Venter
- Department of Chemistry, University of Cape Town, Rondebosch, Cape Town, 7701, South Africa
| | - Mandla Mabunda
- Department of Chemistry, University of Cape Town, Rondebosch, Cape Town, 7701, South Africa
| | - James Biwi
- Department of Chemistry, University of Cape Town, Rondebosch, Cape Town, 7701, South Africa
| | - Suman K Samanta
- Faculty of Science, Assam down town University, Sankar Madhab Path, Gandi Nagar, Panikhaiti, Guwahati, 781026, Assam, India
| | - Johan D Klinck
- Department of Chemistry and Polymer Science, Stellenbosch University, Matieland, 7600, South Africa
| | - Shivendra V Singh
- Department of Pharmacology & Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
- University of Pittsburgh School of Medicine, UPMC Hillman Cancer Centre, Pittsburgh, Pennsylvania, USA
| | - Roger Hunter
- Department of Chemistry, University of Cape Town, Rondebosch, Cape Town, 7701, South Africa
| | - Catherine H Kaschula
- Department of Chemistry and Polymer Science, Stellenbosch University, Matieland, 7600, South Africa
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Scirè A, Casari G, Romaldi B, de Bari L, Antognelli C, Armeni T. Glutathionyl Hemoglobin and Its Emerging Role as a Clinical Biomarker of Chronic Oxidative Stress. Antioxidants (Basel) 2023; 12:1976. [PMID: 38001829 PMCID: PMC10669486 DOI: 10.3390/antiox12111976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Revised: 11/02/2023] [Accepted: 11/04/2023] [Indexed: 11/26/2023] Open
Abstract
Hemoglobin is one of the proteins that are more susceptible to S-glutathionylation and the levels of its modified form, glutathionyl hemoglobin (HbSSG), increase in several human pathological conditions. The scope of the present review is to provide knowledge about how hemoglobin is subjected to S-glutathionylation and how this modification affects its functionality. The different diseases that showed increased levels of HbSSG and the methods used for its quantification in clinical investigations will be also outlined. Since there is a growing need for precise and reliable methods for markers of oxidative stress in human blood, this review highlights how HbSSG is emerging more and more as a good indicator of severe oxidative stress but also as a key pathogenic factor in several diseases.
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Affiliation(s)
- Andrea Scirè
- Department of Life and Environmental Sciences (Di.S.V.A.), Università Politecnica delle Marche, 60131 Ancona, Italy
| | - Giulia Casari
- Department of Odontostomatologic and Specialized Clinical Sciences, Università Politecnica delle Marche, 60131 Ancona, Italy; (G.C.); (B.R.); (T.A.)
| | - Brenda Romaldi
- Department of Odontostomatologic and Specialized Clinical Sciences, Università Politecnica delle Marche, 60131 Ancona, Italy; (G.C.); (B.R.); (T.A.)
| | - Lidia de Bari
- Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies (IBIOM), National Research Council (CNR), 70126 Bari, Italy;
| | - Cinzia Antognelli
- Department of Medicine and Surgery, Università Degli Studi di Perugia, 06129 Perugia, Italy;
| | - Tatiana Armeni
- Department of Odontostomatologic and Specialized Clinical Sciences, Università Politecnica delle Marche, 60131 Ancona, Italy; (G.C.); (B.R.); (T.A.)
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Cooper CE, Bird M, Sheng X, Choi JW, Silkstone GGA, Simons M, Syrett N, Piano R, Ronda L, Bettati S, Paredi G, Mozzarelli A, Reeder BJ. Stability of Maleimide-PEG and Mono-Sulfone-PEG Conjugation to a Novel Engineered Cysteine in the Human Hemoglobin Alpha Subunit. Front Chem 2021; 9:707797. [PMID: 34381760 PMCID: PMC8350135 DOI: 10.3389/fchem.2021.707797] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Accepted: 07/07/2021] [Indexed: 12/14/2022] Open
Abstract
In order to use a Hemoglobin Based Oxygen Carrier as an oxygen therapeutic or blood substitute, it is necessary to increase the size of the hemoglobin molecule to prevent rapid renal clearance. A common method uses maleimide PEGylation of sulfhydryls created by the reaction of 2-iminothiolane at surface lysines. However, this creates highly heterogenous mixtures of molecules. We recently engineered a hemoglobin with a single novel, reactive cysteine residue on the surface of the alpha subunit creating a single PEGylation site (βCys93Ala/αAla19Cys). This enabled homogenous PEGylation by maleimide-PEG with >80% efficiency and no discernible effect on protein function. However, maleimide-PEG adducts are subject to deconjugation via retro-Michael reactions and cross-conjugation to endogenous thiol species in vivo. We therefore compared our maleimide-PEG adduct with one created using a mono-sulfone-PEG less susceptible to deconjugation. Mono-sulfone-PEG underwent reaction at αAla19Cys hemoglobin with > 80% efficiency, although some side reactions were observed at higher PEG:hemoglobin ratios; the adduct bound oxygen with similar affinity and cooperativity as wild type hemoglobin. When directly compared to maleimide-PEG, the mono-sulfone-PEG adduct was significantly more stable when incubated at 37°C for seven days in the presence of 1 mM reduced glutathione. Hemoglobin treated with mono-sulfone-PEG retained > 90% of its conjugation, whereas for maleimide-PEG < 70% of the maleimide-PEG conjugate remained intact. Although maleimide-PEGylation is certainly stable enough for acute therapeutic use as an oxygen therapeutic, for pharmaceuticals intended for longer vascular retention (weeks-months), reagents such as mono-sulfone-PEG may be more appropriate.
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Affiliation(s)
- Chris E Cooper
- School of Life Sciences, University of Essex, Colchester, United Kingdom
| | | | | | | | - Gary G A Silkstone
- School of Life Sciences, University of Essex, Colchester, United Kingdom
| | - Michelle Simons
- School of Life Sciences, University of Essex, Colchester, United Kingdom
| | - Natalie Syrett
- School of Life Sciences, University of Essex, Colchester, United Kingdom
| | - Riccardo Piano
- Department of Medicine and Surgery, University of Parma, Parma, Italy
| | - Luca Ronda
- Department of Medicine and Surgery, University of Parma, Parma, Italy.,Institute of Biophysics, National Research Council, Pisa, Italy
| | - Stefano Bettati
- Department of Medicine and Surgery, University of Parma, Parma, Italy.,Institute of Biophysics, National Research Council, Pisa, Italy
| | | | - Andrea Mozzarelli
- Institute of Biophysics, National Research Council, Pisa, Italy.,Department of Food and Drug, University of Parma, Parma, Italy
| | - Brandon J Reeder
- School of Life Sciences, University of Essex, Colchester, United Kingdom
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Meng F, Kassa T, Strader MB, Soman J, Olson JS, Alayash AI. Substitutions in the β subunits of sickle-cell hemoglobin improve oxidative stability and increase the delay time of sickle-cell fiber formation. J Biol Chem 2019; 294:4145-4159. [PMID: 30630954 PMCID: PMC6422104 DOI: 10.1074/jbc.ra118.006452] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Revised: 01/07/2019] [Indexed: 01/13/2023] Open
Abstract
After reacting with hydrogen peroxide (H2O2), sickle-cell hemoglobin (HbS, βE6V) remains longer in a highly oxidizing ferryl form (HbFe4+=O) and induces irreversible oxidation of “hot-spot” amino acids, including βCys-93. To control the damaging ferryl heme, here we constructed three HbS variants. The first contained a redox-active Tyr in β subunits (F41Y), a substitution present in Hb Mequon; the second contained the Asp (K82D) found in the β cleft of Hb Providence; and the third had both of these β substitutions. Both the single Tyr-41 and Asp-82 constructs lowered the oxygen affinity of HbS but had little or no effects on autoxidation or heme loss kinetics. In the presence of H2O2, both rHbS βF41Y and βF41Y/K82D enhanced ferryl Hb reduction by providing a pathway for electrons to reduce the heme via the Tyr-41 side chain. MS analysis of βCys-93 revealed moderate inhibition of thiol oxidation in the HbS single F41Y variant and dramatic 3- to 8-fold inhibition of cysteic acid formation in rHbS βK82D and βF41Y/K82D, respectively. Under hypoxia, βK82D and βF41Y/K82D HbS substitutions increased the delay time by ∼250 and 600 s before the onset of polymerization compared with the rHbS control and rHbS βF41Y, respectively. Moreover, at 60 °C, rHbS βK82D exhibited superior structural stability. Asp-82 also enhanced the function of Tyr as a redox-active amino acid in the rHbS βF41Y/K82D variant. We conclude that the βK82D and βF41Y substitutions add significant resistance to oxidative stress and anti-sickling properties to HbS and therefore could be potential genome-editing targets.
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Affiliation(s)
- Fantao Meng
- From the Laboratory of Biochemistry and Vascular Biology, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, Maryland 20993 and
| | - Tigist Kassa
- From the Laboratory of Biochemistry and Vascular Biology, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, Maryland 20993 and
| | - Michael Brad Strader
- From the Laboratory of Biochemistry and Vascular Biology, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, Maryland 20993 and
| | - Jayashree Soman
- the BioSciences Department, Rice University, Houston, Texas 77251
| | - John S Olson
- the BioSciences Department, Rice University, Houston, Texas 77251
| | - Abdu I Alayash
- From the Laboratory of Biochemistry and Vascular Biology, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, Maryland 20993 and
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