Brief Article pubs.acs.org/jmc
Design, Synthesis, and Identification of 4″α-Azidoethyl-cyclic ADPCarbocyclic-ribose as a Highly Potent Analogue of Cyclic ADPRibose, a Ca2+-Mobilizing Second Messenger Takatoshi Sato,† Mizuki Watanabe,† Takayoshi Tsuzuki,† Satoshi Takano,† Takashi Murayama,‡ Takashi Sakurai,‡ Tomoshi Kameda,§ Hayato Fukuda,† Mitsuhiro Arisawa,†,⊥ and Satoshi Shuto*,†,∥ †
Faculty of Pharmaceutical Sciences, Hokkaido University, Kita-ku, Sapporo 060-0812, Japan Department of Pharmacology, Juntendo University School of Medicine, Hongo, Bunkyo-ku, Tokyo 113-8421, Japan § Computational Biology Research Center (CBRC), National Institute of Advanced Industrial Science and Technology (AIST), 2-4-7 Aomi, Koutou-ku, Tokyo 135-0064, Japan ∥ Center for Research and Education on Drug Discovery, Hokkaido University, Kita-ku, Sapporo 060-0812, Japan ‡
S Supporting Information *
ABSTRACT: Cyclic adenosine diphosphate-carbocyclic-ribose (cADPcR, 2) is a stable equivalent of cyclic adenosine diphosphate-ribose (cADPR, 1), a Ca2+-mobilizing second messenger. On the basis of the structure−activity relationship of cADPR-related compounds and three-dimensional structural modeling of cADPcR, we designed and synthesized cyclic-ADP4″α-azidoethyl carbocyclic-ribose (N3-cADPcR, 3) to demonstrate that it has a highly potent Ca2+-mobilizing activity (EC50 = 24 nM). N3-cADPcR will be a useful precursor for the preparation of biological tools effective to investigate cADPRmediated signaling pathways.
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INTRODUCTION Cyclic ADP-ribose (cADPR, 1, Figure 1),1 a metabolite of NAD+ (nicotinamide adenine dinucleotide), mobilizes intra-
that use cADPR are still needed because of the biological importance. In particular, the target proteins of cADPR must be identified. Ca2+-release by cADPR occurs via the ryanodine receptor.3 The action of cADPR on the ryanodine receptor seems to require additional protein factors such as calmodulin3 or FK506-binding protein.4 However, the target proteins of cADPR have not been confirmed. In cells, cADPR is synthesized from NAD+ by ADP-ribosyl cyclase and acts as a Ca2+-mobilizing second messenger; it is rapidly hydrolyzed by cADPR hydrolase to give the inactive metabolite ADP-ribose under physiological conditions.2 cADPR is also known to be readily hydrolyzed nonenzymatically at the unstable N1-glycosidic linkage of its adenine moiety to give ADP-ribose, even in neutral aqueous solution.5 Consequently, the biological and chemical instability of cADPR due to its positively charged N1-riboside structure limits further studies of its physiological roles. In our continued studies of cADPR-related bioorganic chemistry studies,6 we previously designed and synthesized cyclic ADP-carbocyclic ribose (cADPcR, 2) as a stable equivalent of cADPR.6c In fact, cADPcR is chemically and biologically stable and effectively mobilizes Ca2+ in various biological systems.6c,f Therefore, due to its biological potency
Figure 1. Structures of cADPR (1), cADPcR (2), and N3-cADPcR (3).
cellular Ca2+ in various cells types, such as pancreatic β-cells, smooth muscle, cardiac muscle, T-lymphocytes, and cerebellar neurons in mammalian cells, and therefore cADPR is now recognized as a general second messenger involved in intracellular Ca2+ signaling.2 As a second messenger, cADPcR is involved in a variety of physiological processes, while these have not been fully clarified.2 Therefore, intensive studies of the signaling pathways © XXXX American Chemical Society
Received: March 23, 2016
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DOI: 10.1021/acs.jmedchem.6b00437 J. Med. Chem. XXXX, XXX, XXX−XXX
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and stability, cADPcR can be used as a lead structure for developing biological tools to investigate cADPR-related Ca2+mobilizing signaling pathways. Derivatives of cADPcR attaching functional groups, such as biotin, photoaffinity labeling, or fluorescent groups, can be useful biological tools, particularly for identifying the target biomolecules of cADPR. To develop these useful biological tools, it is essential to confirm the position in cADPcR at which the functional group can be attached without decreasing the biological potency. Here we describe the design and synthesis of cyclic-ADP-4″α-azidoethyl carbocyclic-ribose (N3-cADPcR, 3), which can be a useful precursor compound for developing biological tools due to its potent Ca2+-mobilizing activity and also its azidoethyl-branched structure effective for conjugating the desired functional groups.
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RESULTS AND DISCUSSION Design of N3-cADPcR (3). We aimed to develop the biological tools that are highly potent cADPcR derivatives conjugating a functional group, the general structure of which is shown in Figure 2a. To find out the position suitable for the functional group conjugation without decreasing the biological potency, we have designed and synthesized various derivatives of cADPcR, but these were unsuccessful; substitutions at the 6-, 7-, or 8-position in the adenine moiety6b,e,j and the 2″, 3″, or 5″-position in the N1-carbocyclic ribose moiety6f−h in cADPcR resulted in decreased Ca2+-mobilizing activity. In addition, modifications at the 7- and 8-positions in the adenine moiety,7 the 3′-position of the N9-ribose moiety,8 and the phosphate moiety9 in cADPR are also reported to weaken the activity. These previous results are summarized in Figure 2b. Thus, determining a suitable position for the functional groupconnecting modification in cADPR and/or cADPcR was key to developing the desired effective biological tools. We confirmed the three-dimensional structure of cADPcR by NOE-based molecular dynamics6i (Figure 2c). Considering the structure−activity relationship (SAR) findings that 6-NH2 and the pyrophosphate moieties are essential for the biological activity,6b,9 we expected that the 4″α-position, which is rather far from the two essential moieties in the three-dimensional cADPcR structure, might not be important for recognition by the target biomolecules. Thus, we designed 4″α-branched cADPcR derivative 3 (N3-cADPcR) as the synthetic target in which the azido group can be effectively used for connecting functional groups by click chemistry. Synthesis of N3-cADPcR (3). The synthetic scheme of the target N3-cADPcR (3) is shown as Scheme 1. We planned to construct the N1-carbocyclic-ribosyl adenosine derivative 6 by an adenine ring-closure reaction between the 4α-branched carbocyclic-ribosylamine 4, which has a quaternary stereogenic carbon center at the 4-position, and a known imidazole nucleoside derivative 5 prepared from inosine.10 Stereocontrolled construction of quaternary stereogenic carbon centers is one of the most challenging issues in organic chemistry, but we recently succeeded in synthesizing the 4αbranched carbocyclic-ribosylamine 4,11 in which the key quaternary carbon center was effectively constructed using a radical cyclization/ring-enlargement reaction with a silicon tether.12 Thus, the 4α-branched carbocyclic-ribosylamine 4 in hand, its reaction with the imidazole nucleoside derivative 5 in the presence of K2CO3 in DMF/THF effectively induced adenine ring closure to produce the desired N1-carbocyclicribosyl adenosine derivative 6. After protection of the 5″hydroxyl of 6 with a dimethoxytrityl (DMTr) group,
Figure 2. (a) General structure of the desired biological tools, which are functional-group-conjugated highly potent cADPcR analogues; (b) previously modified positions in cADPR (1) or cADPcR (2); (c) three-dimensional structure of cADPcR based on molecular dynamics calculations with a simulated annealing method using NOE data.
subsequent removal of the TBS group at the 5′-hydroxyl gave 8, and treatment with S,S′- diphenylphosphorodithioate (PSS)/ 2,4,6-triisopropylbenzenesulfonyl chloride (TPSCl)/pyridine system13 produced the 5′-diphenylphosphoroditioate 8. Acidic removal of the 5″-O-DMTr group of 8 afforded 9. The 5′hydroxyl of 9 was successfully phosphorylated by treatment with MeOPOCl2 in pyridine at −30 °C14 and quenching with triethylammonium acetate (TEAA) buffer, and the resulting phosphorylation product, without purification, was further treated with H3PO2 and Et3N in pyridine to remove a phenylthio group,15 providing 10, the substrate for the next intramolecular condensation reaction, after purification by ionexchange chromatography. When a solution of 10 in pyridine B
DOI: 10.1021/acs.jmedchem.6b00437 J. Med. Chem. XXXX, XXX, XXX−XXX
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Scheme 1. Synthetic Scheme for the Target N3-cADPcR (3)a
a
Reagents and conditions: (a) K2CO3, DMF/THF, 69%; (b) (1) DMTrCl, py, (2) TBAF, AcOH, THF, 64%; (c) PSS, TPSCl, py, 69%; (d) AcOH, CH2Cl2, 76%; (e) (1) MeOPOCl2, py, −30 °C, then TEAA buffer, (2) H3PO2, Et3N, py, 0 °C to rt, 28%; (f) AgNO3, Et3N, MS3A. py, 69%; (g) (1) 60% HCO2H, (2) 28% NH3, quant.
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CONCLUSION In summary, considering the efficient bioisosteric property of carbocyclic-ribose, the previous structure−activity relationship results, and the three-dimensional modeling structure of cADPcR, we designed N3-cADPcR (3) as a prototype compound to develop biological tools for investigating the Ca2+-mobilizing signaling pathways. Starting from the (4αazidoethyl)carbocyclic ribose derivative 4, the target N3cADPcR (3) was synthesized via an intramolecular condensation reaction to form an 18-membered pyrophosphate ring as the key step. N3-cADPcR (3) was identified as a useful precursor of biological tools for investigating cADPR-mediated signaling pathways due to the azidoethyl-branched structure.18
was added slowly to a mixture of a large excess of AgNO3 and Et3N in the presence of MS3A in pyridine at room temperature,6b,c,13 the desired 18-membered pyrophosphate ring was effectively constructed to produce the cyclization product 11 in 69% yield. Finally, simultaneous removal of the two isopropylidene groups of 11 furnished the target N3cADPcR (3).16 Ca2+-Mobilizing Ability of N3-cADPcR (3). We used sea urchin homogenate for biological evaluation of the Ca2+mobilizing effects of the compounds, which are commonly used for biological evaluations of cADPR-related compounds. Thus, we examined the Ca2+-mobilizing ability of N3-cADPcR (3), as well as cADPR (1) and cADPcR (2), by fluorometrically monitoring Ca2+ with Hemicentrotus pulcherrimus sea urchin egg homogenate, and the results are shown in Figure 3.17 cADPR
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EXPERIMENTAL SECTION
General Procedure. 1H NMR spectra were recorded in CDCl3 at ambient temperature, unless otherwise noted, at 400 or 500 MHz, with TMS as an internal standard. 13C NMR spectra were recorded in CDCl3 at ambient temperature at 100 or 125 MHz. Silica gel column chromatography was performed with silica gel 60 N (spherical, neutral, 63-210 μm, Kanto Chemical Co., Inc.). Flash column chromatography was performed with silica gel 60 N (spherical, neutral, 40−50 μm, Kanto Chemical Co., Inc.). The purity of final compound was confirmed to be greater than 95% by HPLC analysis. Analytical HPLC was performed with YMC J’sphere ODS-M80 (250 mm × 4.6 mm), A soln 5% MeCN in 0.1 M triethylamomonium acetate buffer, B soln 80% MeCN in 0.1 M triethylamomonium acetate buffer, B concn 0− 100% (30 min), 1 mL/min. 4″α-Azidoethyl-cyclic ADP-Carbocyclic Ribose (N3-cADPcR, 3). A solution of 11 (6 mg, 8.0 μmol) in aqueous 60% HCO2H (0.50 mL) was stirred at room temperature for 38 h and then evaporated. After the residue was coevaporated with H2O (2 mL × 3), a solution of the residue in aqueous 28% NH3 (1.0 mL) was stirred at the same temperature for 2 h, and then evaporated. After dissolving the residue in H2O (1 mL) and TEAB buffer (0.1 M, pH 7.0, 80 μL), the resulting solution was lyophilized to give 3 (6 mg, quant) as a triethylammonium salt: HPLC purity, 98.2%. 1H NMR (500 MHz, D2O) δ 8.88 (1H, s, H-2), 8.40 (1H, s, H-8), 6.07 (1H, d, H-1′, J = 5.9 Hz), 5.26 (1H, dd, H-2′, J = 5.9, 5.0 Hz), 5.00 (1H, ddd, H-1″, J = 10.3, 6.7, 4.0 Hz), 4.70 (1H, dd, H-2″, J = 6.7, 4.9 Hz), 4.56 (1H, ddd, H-5′, J = 10.5, 8.6, 2.3 Hz), 4.39 (1H, dt, H-5′, J = 8.6, 2.3 Hz), 4.06− 4.02 (3H, m, H-4′, H-3″, H-5″), 3.79 (1H, dd, H-5″, J = 10.9, 1.4 Hz), 3.54−3.41 (2H, m, H-8″), 2.81 (1H, dd, H-6″, J = 16.2, 4.0 Hz), 2.73 (1H, dd, H-6″, J = 16.2, 10.3 Hz), 1.97 (2H, t, H-7″, J = 7.7 Hz). 13C NMR (100 MHz, D2O) δ 162.9, 156.6, 155.5, 154.4, 131.1, 101.1,
Figure 3. Ca2+-Mobilizing ability of cADPR (1), cADPcR (2), and N3cADPcR (3) in sea urchin egg homogenate.
released Ca2+ from the homogenate in a concentrationdependent manner with an EC50 value of 213 nM, and cADPcR exhibited more potent activity (EC50 = 54 nM) than cADPR (EC50 = 213 nM). N3-cADPcR exhibited highly potent Ca2+-mobilizing ability (EC50 = 24 nM), which was about 9-fold more potent than the natural second messenger cADPR and even more potent than cADPcR. Thus, we successfully confirmed that the 4″α-position is suitable for connecting functional groups without decreasing the biological potency of cADPR and its analogues. C
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95.5, 90.5, 86.3, 83.8, 81.4, 78.4, 76.0, 75.3, 75.2, 59.3, 59.2, 57.7, 45.3, 42.4. 31P NMR (162 MHz, D2O) δ −10.1 (d, J = 13.0 Hz), −10.4 (d, J = 13.0 Hz). UV (D2O) λmax = 258 nm. HR-MS (ESI, negative) calcd for C18H25O12N8P2 607.1099 [M−], found 607.1073.
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(4) (a) Noguchi, N.; Takasawa, S.; Nata, K.; Tohgo, A.; Kato, I.; Ikehata, F.; Yonekura, H.; Okamoto, H. Cyclic ADP-ribose binds to FK506-binding protein 12.6 to release Ca2+ from islet microsomes. J. Biol. Chem. 1997, 272, 3133−3136. (b) Wang, Y. X.; Zheng, Y. M.; Mei, Q. B.; Wang, Q. S.; Collier, M. L.; Fleischer, S.; Xin, H. B.; Kotlikoff, M. FKBP12.6 and cADPR regulation of Ca2+ release in smooth muscle cells. Am. J. Physiol. Cell Physiol. 2004, 286, C538− C546. (c) Zheng, J.; Wenzhi, B.; Miao, L.; Hao, Y.; Zhang, X.; Yin, W.; Pan, J.; Yuan, Z.; Song, B.; Ji, G. Ca2+ release induced by cADP-ribose is mediated by FKBP12.6 proteins in mouse bladder smooth muscle. Cell Calcium 2010, 47, 449−457. (d) Tang, W. X.; Chen, Y. F.; Zou, A. P.; Campbell, W. B.; Li, P. L. Role of FKBP12.6 in cADPR-induced activation of reconstituted ryanodine receptors from arterial smooth muscle. Am. J. Physiol. Heart Circ. Physiol. 2002, 282, H1304−H1310. (5) Lee, H. C.; Aarhus, R. Wide distribution of an enzyme that catalyzes the hydrolysis of cyclic ADP-ribose. Biochim. Biophys. Acta, Protein Struct. Mol. Enzymol. 1993, 1164, 68−74. (6) (a) Shuto, S.; Shirato, M.; Sumita, Y.; Ueno, Y.; Matsuda, A. Synthesis of cyclic IDP-carbocyclic-ribose, a stable mimic of cyclic ADP-ribose. Significant facilization of the intramolecular condensation reaction of N-1-(carbocyclic-ribosyl)inosine 5′,6″-diphosphate derivatives by an 8-bromo-substitution at the hypozanthine moiety. J. Org. Chem. 1998, 63, 1986−1994. (b) Fukuoka, M.; Shuto, S.; Minakawa, N.; Ueno, Y.; Matsuda, A. An efficient synthesis of cyclic IDP- and cyclic 8-bromo-IDP-carbocyclic-riboses using a modified Hata condensation method to form an intramolecular pyrophosphate linkage as a key step. An entry to a general method for the chemical synthesis of cyclic ADP-ribose analogues. J. Org. Chem. 2000, 65, 5238−5248. (c) Shuto, S.; Fukuoka, M.; Manikowsky, M.; Ueno, T.; Nakano, T.; Kuroda, R.; Kuroda, H.; Matsuda, A. Total synthesis of cyclic ADP-carbocyclic-ribose, a stable mimic of Ca2+-mobilizing second messenger cyclic ADP-ribose. J. Am. Chem. Soc. 2001, 123, 8750−8759. (d) Guse, A. H.; Cakir-Kiefer, C.; Fukuoka, M.; Shuto, S.; Weber, K.; Bailey, V. C.; Matsuda, A.; Mayr, G. W.; Oppenheimer, N.; Schuber, F.; Potter, B. V. L. Novel hydrolysis-resistant analogues of cyclic ADP-ribose: modification of the “northern” ribose and calcium release activity. Biochemistry 2002, 41, 6744−6751. (e) Shuto, S.; Fukuoka, M.; Kudoh, T.; Garnham, C.; Galione, A.; Potter, B. V. L.; Matsuda, A. Convergent synthesis and unexpected Ca2+-mobilizing activity of 8-substituted analogues of cyclic ADP-carbocyclic-ribose, a stable mimic of the Ca2+-mobilizing second messenger cyclic ADPribose. J. Med. Chem. 2003, 46, 4741−4749. (f) Kudoh, T.; Fukuoka, M.; Ichikawa, S.; Murayama, T.; Ogawa, Y.; Hashii, M.; Higashida, H.; Kunerth, S.; Weber, K.; Guse, A. H.; Potter, B. V. L.; Matsuda, A.; Shuto, S. Synthesis of stable and cell-type selective analogues of cyclic ADP-ribose, a Ca2+-mobilizing second messenger. Structure–activity relationship of the N1-ribose. J. Am. Chem. Soc. 2005, 127, 8846− 8855. (g) Kudoh, T.; Murayama, T.; Matsuda, A.; Shuto, S. Substitution at the 8-position of 3″-deoxy-cyclic ADP-carbocyclicribose, a highly potent Ca2+-mobilizing agent, provides partial agonist. Bioorg. Med. Chem. 2007, 15, 3032−3040. (h) Sakaguchi, N.; Kudoh, T.; Tsuzuki, T.; Murayama, T.; Sakurai, T.; Matsuda, A.; Arisawa, M.; Shuto, S. Synthesis of 5″-branched derivatives of cyclic ADPcarbocyclic-ribose, a potent Ca2+-mobilizing agent: the first antagonists modified at the N1-ribose moiety. Bioorg. Med. Chem. Lett. 2008, 18, 3814−3818. (i) Tsuzuki, T.; Sakaguchi, N.; Kudoh, T.; Takano, S.; Uehara, M.; Murayama, T.; Sakurai, T.; Hashii, M.; Higashida, H.; Weber, K.; Guse, A. H.; Kameda, T.; Hirokawa, T.; Kumaki, Y.; Potter, B. V. L.; Fukuda, H.; Arisawa, M.; Shuto, S. Design and synthesis of cyclic ADP-4-thioribose as a stable equivalent of cyclic ADP-ribose, a Ca2+-mobilizing second messenger. Angew. Chem., Int. Ed. 2013, 52, 6633−6637. (j) Takano, S.; Tsuzuki, T.; Murayama, T.; Sakurai, T.; Fukuda, H.; Arisawa, M.; Shuto, S. Synthesis of 7-Deaza-Cyclic Adenosine-5′-Diphosphate-Carbocyclic-Ribose and its 7-Bromo Derivative as Intracellular Ca2+-Mobilizing Agents. J. Org. Chem. 2015, 80, 6619−6627. (7) (a) Walseth, T. F.; Lee, H. C. Synthesis and characterization of antagonists of cyclic-ADP-ribose-induced Ca2+ release. Biochim. Biophys. Acta, Mol. Cell Res. 1993, 1178, 235−242. (b) Bailey, V. C.;
ASSOCIATED CONTENT
S Supporting Information *
The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acs.jmedchem.6b00437. Experimental synthetic procedures, 1H and 31P NMR charts of compounds (PDF) Molecular formula strings (CSV)
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AUTHOR INFORMATION
Corresponding Author
*Phone/fax: +88-11-7063769. E-mail:
[email protected]. jp. Present Address ⊥
For M.A.: Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan. Author Contributions
The manuscript was prepared through contributions of all authors. All authors have given approval to the final version of the manuscript Notes
The authors declare no competing financial interest.
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ABBREVIATIONS USED cADPR, cyclic adenosine diphosphate-ribose; cADPcR, cyclic adenosine diphosphate-carbocyclic-ribose; NAD, nicotinamide adenine dinucleotide; DMTr, dimethoxytrityl; PSS, S,S′diphenylphosphorodithioate; TPSCl, 2,4,6-triisopropylbenzenesulfonyl chloride; SAR, structure−activity relationship
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REFERENCES
(1) Clapper, D. L.; Walseth, T. F.; Dargie, P. J.; Lee, H. C. Pyridine nucleotide metabolite stimulate calcium release from sea urchin egg microsomes desensitized to inositol triphosphate. J. Biol. Chem. 1987, 262, 9561−9568. (2) (a) Galione, A. Cyclic ADP-ribose: a new way to control calcium. Science 1993, 259, 325−326. (b) Guse, A. H. Cyclic ADP-ribose. J. Mol. Med. 2000, 78, 26−35. (c) Higashida, H.; Hashii, M.; Yokoyama, S.; Hoshi, N.; Chen, X. L.; Egorova, A.; Noda, M.; Zhang, J. S. Cyclic ADP-ribose as a second messenger revisited from a new aspect of signal transduction from receptors to ADP-ribosyl cyclase. Pharmacol. Ther. 2001, 90, 283−296. (d) Cyclic ADP-Ribose and NAADP: Structures, Metabolism and Functions; Lee, H. C., Ed.; Kluwer Academic Publishers: Dordrecht, The Netherlands, 2002. (e) Jin, D.; Liu, H.-X.; Hirai, H.; Torashima, T.; Nagai, T.; Lopatina, O.; Shnayder, N. A.; Yamada, K.; Noda, M.; Seike, T.; Fujita, K.; Takasawa, S.; Yokoyama, S.; Koizumi, K.; Shiraishi, Y.; Tanaka, S.; Hashii, M.; Yoshihara, T.; Higashida, K.; Islam, M. S.; Yamada, N.; Hayashi, K.; Noguchi, N.; Kato, I.; Okamoto, H.; Matsushima, A.; Salmina, A.; Munesue, T.; Shimizu, N.; Mochida, S.; Asano, M.; Higashida, H. CD38 is critical for social behaviour by regulating oxytocin secretion. Nature 2007, 446, 41−45. (f) Lee, H. C. Cyclic ADP-ribose and nicotinic acid adenine dinucleotide phosphate (NAADP) as messengers for calcium mobilization. J. Biol. Chem. 2012, 287, 31633−31640. (g) Guse, A. J. Calcium mobilizing second messengers derived from NAD. Biochim. Biophys. Acta, Proteins Proteomics 2015, 1854, 1132−1137. (3) Lee, H. C.; Aarhus, R.; Graeff, R.; Gurnack, M. E.; Walseth, T. F. Cyclic ADP ribose activation of the ryanodine receptor is mediated by calmodulin. Nature 1994, 370, 307−309. D
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Sethi, J. K.; Fortt, S. M.; Galione, A.; Potter, B. V. L. 7-Deaza cyclic adenosine 5′-diphophate ribose: first example of a Ca2+-mobilizing partial agonist related to cyclic adenosine 5′-diphosphate ribose. Chem. Biol. 1997, 4, 51−60. (8) (a) Aarhus, R.; Graeff, R. M.; Dickey, D. M.; Walseth, T. F.; Hon, C. L. ADP-ribosyl cyclase and CD38 catalyze the synthesis of a calcium-mobilizing metabolite. J. Biol. Chem. 1995, 270, 30327−30333. (b) Ashamu, G. A.; Sethi, J. K.; Galione, A.; Potter, B. V. L. Roles for adenosine ribose hydroxyl groups in cyclic adenosine 5′-Diphosphate ribose-mediated Ca2+ release. Biochemistry 1997, 36, 9509−9517. (9) (a) Xu, L.; Walseth, T. F.; Slama, J. T. Cyclic ADP-ribose analogues containing the methy- lenebisphosphonate linkage: effect of pyrophosphate modifications on Ca2+ release activity. J. Med. Chem. 2005, 48, 4177−4181. (b) Swarbrick, J. M.; Graeff, R.; Garnham, C.; Thomas, M. P.; Galione, A.; Potter, B. V. L. Click cyclic ADP-ribose: a neutral second messenger mimic. Chem. Commun. 2014, 50, 2458− 2461. (10) Hutchinson, E. J.; Taylor, B. F.; Blackburn, G. M. Stereospecific synthesis of 1,9-bis(β-D-glycosyl)adenines: a chemical route to stable analogues of cyclic-ADP ribose (cADPR). J. Chem. Soc. Chem. Commun. 1997, 1859−1860. (11) Sato, T.; Tsuzuki, T.; Takano, S.; Kato, K.; Fukuda, H.; Arisawa, M.; Shuto, S. Construction of a chiral quaternary carbon center by a radical cyclization/ring−enlargement reaction: synthesis of 4αazidoethyl carbocyclic ribose, a key unit for the synthesis of cyclic ADP-ribose derivatives of biological importance. Tetrahedron 2015, 71, 5407−5413. (12) Shuto, S.; Sugimoto, I.; Abe, H.; Matsuda, A. Mechanistic study of the ring-enlargement reaction of (3-oxa-2-silacyclopentyl)methyl radicals into 4-oxa-3-silacyclohexyl radicals. Evidence for a pentavalent silicon-bridging radical transition state in 1,2-rearrangement reactions of β-silyl radicals. J. Am. Chem. Soc. 2000, 122, 1343−1351. (13) Sekine, M.; Nishiyama, S.; Kamimura, T.; Osaki, Y.; Hata, T. Chemical synthesis of capped oligoribonucleotides, m7G5′ ppp AUGACC. Bull. Chem. Soc. Jpn. 1985, 58, 850−860. (b) Sekine, M.; Hata, T. Chemical synthesis of oligonucleotides by use of phenylthio group. Curr. Org. Chem. 1999, 3, 25−66. (14) Asseline, U.; Thuong, N. T. Oligothymidylates substituted by an acridine derivative in the 5′-position; at both the 5′- and 3′-positions, or on the internucleotidic phosphate. Nucleosides Nucleotides 1988, 7, 431−55. (15) Hata, T.; Kamimura, T.; Urakami, K.; Kohno, K.; Sekine, M.; Kumagai, I.; Shinozaki, K.; Miura, K. A new method for the synthesis of oligodeoxyribonucleotides bearing a 5′-terminal phosphate group. Chem. Lett. 1987, 117−120. (16) The chemical stability of N3-cADPcR (3) was confirmed: after treatment of 3 in TEAA buffer (pH 7.0) at 37 °C for 3 days, its remaining rate was >98% by HPLC analysis. (17) Shiwa, M.; Murayama, T.; Ogawa, Y. Molecular cloning and characterization of ryanodine receptor from unfertilized sea urchin eggs. Am. J. Physiol. Regul. Integr. Comp. Physiol. 2002, 282, R727−737. (18) Treatment of N3-cADPcR (3) with 3-butyn-1-ol as a model alkyne in the presence of CuSO4 in t-BuOH at room temperature effectively produced the corresponding Hüisgen reaction product.
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