General peroxidase activity of a parallel G-quadruplex-hemin DNAzyme formed by Pu39WT - a mixed G-quadruplex forming sequence in the Bcl-2 P1 promoter
Tóm tắt
A 39-base-pair sequence (Pu39WT) located 58 to 19 base pairs upstream of the Bcl-2 P1 promoter has been implicated in the formation of an intramolecular mixed G-quadruplex structure and is believed to play a major role in the regulation of bcl-2 transcription. However, an extensive functional exploration requires further investigation. To further exploit the structure–function relationship of the Pu39WT-hemin DNAzyme, the secondary structure and peroxidase activity of the Pu39WT-hemin complex were investigated. Experimental results showed that when Pu39WT was incubated with hemin, it formed a uniparallel G-quadruplex-hemin complex in K+ or Na+ solution, rather than a mixed hybrid without bound hemin. Also, Pu39WT-hemin showed peroxidase activity (ABTS2−) in the presence of H2O2 to produce the colored radical anion (ABTS•-), which could then be used to determine the parameters governing the catalytic efficiency and reveal the peroxidase activity of the Pu39WT-hemin DNAzyme. These results demonstrate the general peroxidase activity of Pu39WT-hemin DNAzyme, which is an intramolecular parallel G-quadruplex structure. This peroxidase activity of hemin complexed with the G-quadruplex-forming sequence in the Bcl-2 gene promoter may imply a potential mechanism of hemin-mediated cellular injury.
Tài liệu tham khảo
Dai J, Chen D, Jones RA, Hurley LH, Yang D: NMR solution structure of the major G-quadruplex structure formed in the human BCL2 promoter region. Nucleic Acids Res. 2006, 34: 5133-5144.
Dai J, Dexheimer TS, Chen D, Carver M, Ambrus A, Jones RA, Yang D: An intramolecular G-quadruplex structure with mixed parallel/antiparallel G-strands formed in the human BCL-2 promoter region in solution. J Am Chem Soc. 2006, 128: 1096-1098.
Dexheimer TS, Sun D, Hurley LH: Deconvoluting the structural and drug-recognition complexity of the G-quadruplex-forming region upstream of the bcl-2 P1 promoter. J Am Chem Soc. 2006, 128: 5404-5415.
Huppert JL, Balasubramanian S: G-quadruplexes in promoters throughout the human genome. Nucleic Acids Res. 2007, 35: 406-413.
Young RL, Korsmeyer SJ: A negative regulatory element in the bcl-2 5’-untranslated region inhibits expression from an upstream promoter. Mol Cell Biol. 1993, 13: 3686-3697.
Clem RJ, Cheng EH, Karp CL, Kirsch DG, Ueno K, Takahashi A, Kastan MB, Griffin DE, Earnshaw WC, Veliuona MA, Hardwick JM: Modulation of cell death by Bcl-XL through caspase interaction. Proc Natl Acad Sci U S A. 1998, 95: 554-559.
Cristofanon S, Nuccitelli S, D’Alessio M, Radogna F, De Nicola M, Bergamaschi A, Cerella C, Magrini A, Diederich M, Ghibelli L: Oxidative upregulation of Bcl-2 in healthy lymphocytes. Ann N Y Acad Sci. 2006, 1091: 1-9.
Haddad JJ: On the antioxidant mechanisms of Bcl-2: a retrospective of NF-kappaB signaling and oxidative stress. Biochem Biophys Res Commun. 2004, 322: 355-363.
Raghavan SC, Swanson PC, Wu X, Hsieh CL, Lieber MR: A non-B-DNA structure at the Bcl-2 major breakpoint region is cleaved by the RAG complex. Nature. 2004, 428: 88-93.
Travascio P, Li Y, Sen D: DNA-enhanced peroxidase activity of a DNA-aptamer-hemin complex. Chem Biol. 1998, 5: 505-517.
Mergny JL, Li J, Lacroix L, Amrane S, Chaires JB: Thermal difference spectra: a specific signature for nucleic acid structures. Nucleic Acids Res. 2005, 33: e138-
Mergny JL, Lacroix L: UV Melting of G-Quadruplexes. Curr Protoc Nucleic Acid Chem. 2009, Chapter 17: Unit 17 11-
Bugaut A, Balasubramanian S: A sequence-independent study of the influence of short loop lengths on the stability and topology of intramolecular DNA G-quadruplexes. Biochemistry. 2008, 47: 689-697.
Mergny JL, Phan AT, Lacroix L: Following G-quartet formation by UV-spectroscopy. FEBS Lett. 1998, 435: 74-78.
He Y, Tian Y, Mao C: Human telomeric DNA sequences have a peroxidase apoenzyme activity. Mol Biosyst. 2009, 5: 238-240.
Li Y, Li X, Ji X, Li X: Formation of G-quadruplex-hemin DNAzyme based on human telomere elongation and its application in telomerase activity detection. Biosens Bioelectron. 2011, 26: 4095-4098.
Cheng X, Liu X, Bing T, Cao Z, Shangguan D: General peroxidase activity of G-quadruplex-hemin complexes and its application in ligand screening. Biochemistry. 2009, 48: 7817-7823.
Stefan L, Denat F, Monchaud D: Insights into how nucleotide supplements enhance the peroxidase-mimicking DNAzyme activity of the G-quadruplex/hemin system. Nucleic Acids Res. 2012, 40: 8759-8772.