Huai-Feng Mi

Nankai University, Tianjin, Tianjin Shi, China

Are you Huai-Feng Mi?

Claim your profile

Publications (10)35.5 Total impact

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: A novel one-dimensional heterometallic complex, {Cd2[NiL]2(SCN)4(H2O)}n (1), has been synthesized and characterized by single-crystal X-ray analysis, where L is dianion of 2,3-dioxo-5,6,13,14-dibenzo-9,10-cyclohexyl-7,12-bis(ethoxycarbonyl)-1,4,8,11-tetraazacyclotetradeca-7,11-diene. The most striking feature of 1 is that in the structure there is one type of S–S bond (1.823(13)Å) formed by two thiocyanate groups which has not been reported to our knowledge. The DNA cleavage activity of 1 in the presence of H2O2 was compared with those of nickel(II) ion, cadmium(II) ion and corresponding mononuclear precursor NiL (2). The DNA cleavage kinetics was studied and the corresponding activation parameters of 1 were obtained.
    Inorganica Chimica Acta. 01/2009; 362(4):1109-1114.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Nickel is considered a weak carcinogen. Some researches have shown that bound proteins or synthetic ligands may increase the toxic effect of nickel ions. A systematic study of ligand effects on the interaction between nickel complexes and DNA is necessary. Here, we compared the interactions between DNA and six closely related Schiff base tetraazamacrocyclic oxamido nickel(II) complexes NiL(1-3a,1-3b). The structure of one of the six complexes, NiL(3b) has been characterized by single crystal X-ray analysis. All of the complexes can cleave plasmid DNA under physiological conditions in the presence of H(2)O(2). NiL(3b) shows the highest DNA cleavage activity. It can convert supercoiled DNA to nicked DNA then linear DNA in a sequential manner as the complex concentration or reaction time is increased. The cleavage reaction is a typical pseudo-first-order consecutive reaction with the rate constants of 3.27+/-0.14h(-1) (k(1)) and 0.0966+/-0.0042h(-1) (k(2)), respectively, when a complex concentration of 0.6mM is used. The cleavage mechanism between the complex and plasmid DNA is likely to involve hydroxyl radicals as reactive oxygen species. Circular dichronism (CD), fluorescence spectroscopy and gel electrophoresis indicate that the complexes bind to DNA by partial intercalative and groove binding modes, but these binding interactions are not the dominant factor in determining the DNA cleavage abilities of the complexes.
    Journal of Inorganic Biochemistry 05/2008; 102(4):824-32. · 3.20 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Two new mononuclear Mn(II) complexes, Mn(dmbpy)2(OCN)2 (1) and Mn(dmbpy)2(dca)2 (2) (dmbpy=4,4′-dimethyl-2,2′-bipyridine, dca=dicyanamide), have been synthesized and characterized by IR, elemental analysis, and single crystal X-ray analysis. Both complexes have similar molecular structures. The coordination sphere of the Mn(II) ion in 1 or 2 is a seriously distorted octahedron formed by two dmbpy ligands and two OCN− or dca anions in cis positions. For both complexes, the most striking feature is that the mononuclear molecules are linked together by plentiful weak C–H⋯N hydrogen bonds into a compact 3D supramolecular structure. DNA cleavage studies show that the complexes can promote plasmid DNA cleavage in the presence of H2O2 under physiological conditions, and their cleavage activities are obviously both pH value and complex concentration-dependent. The cleavage mechanism between the complexes and plasmid DNA is likely to involve hydroxyl radicals as reactive oxygen species.
    Inorganica Chimica Acta. 01/2008; 361(1):29-35.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Here we introduce a new method for preparing a protein-imprinted polymer with immobilized assistant recognition polymer chains as an additional element of monomer to create effective recognition sites. In this work the bovine serum albumin was used as template and the template protein was selectively assembled with immobilized assistant recognition polymer chains from their library, numerous limited length polymer chains with randomly distributed recognition sites and immobilizing sites. These assemblies of protein and immobilized assistant recognition polymer chains would be adsorbed by the macro porous adsorbent spheres and immobilized by cross-linking polymerization. After removing the template, binding sites that were complementary to the target protein in size, shape and position of recognition groups were exposed, and their confirmation was preserved by the cross-linked structure. The synthesized imprinted polymer was used to adsorb BSA from protein mixtures, and showed a high selectivity.
    Biomaterials 09/2006; 27(24):4381-7. · 8.31 Impact Factor
  • Source
    De-Ming Kong, Han-Xi Shen, Huai-Feng Mi
    [Show abstract] [Hide abstract]
    ABSTRACT: The application of a new fluorogenic probe-based PCR assay (PCR duplex scorpion primer assay) to the detection of Hepatitis B virus (HBV) DNA in human sera was described. Duplex scorpion primer is a modified variant of duplex Amplifluor, and the incorporation of a PCR stopper between probe and primer sequences improve the detection specificity and sensitivity. Combined with PCR amplification, this probe can give unambiguous positive results for the reactions initiated with more than 20 HBV molecules. In addition, the particular unimolecular probing mechanism of this probe makes the use of short target-specific probe sequence possible, which will render this probe applicable in some specific systems.
    Chinese Journal of Chemistry 08/2004; 22(9):903 - 907. · 0.92 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Telomerase, a ribonucleoprotein enzyme, is expected to be a new marker for cancer diagnosis. The development of the telomeric repeat amplification protocol (TRAP) and its modified versions have facilitated the detection of telomerase activity in small tissue and tumour samples. But most of these techniques require complex post-PCR procedures. As for the two real-time quantitative methods (SYBR Green and Amplifluor methods) reported so far, both use fluorogenic probes without specificity. To overcome these problems we developed a new real-time method for the detection of telomerase activity. In this method a duplex scorpion primer and reverse primers with hairpin-like structures were used. The use of duplex scorpion primers shows a series of advantages: the target-specific probe sequence provides higher specificity than the SYBR Green and Amplifluor methods; the unimolecular probing mechanism allow the assay to be conducted under fast cycling conditions and a single operation can be completed in 1.5 h; the closed-tube system reduces the risk of carryover contamination and supports high throughput. This method may be a useful tool to rapidly, specifically and precisely quantify telomerase activity.
    New Journal of Chemistry 01/2004; 28(12). · 2.97 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: A novel method for duplex probes is designed to simulate the TaqMan probe during polymerase chain reaction (PCR). In this method, two partly complementary single-labelled oligonucleotide probes labelled with a fluorophore or a quencher, respectively, are used. At lower temperature the two probes can bind to each other and form a mismatched duplex, in which the fluorophore and quencher are in close proximity and the same energy transfer mechanism as in molecular beacons may occur between them; thus, a quenching efficiency better than conventional TaqMan probes is acquired. In the anneal-extend step of PCR, one single-labelled probe hybridises to the predetermined target and is cleaved by Taq DNA polymerase. Increased fluorescent signal can be observed at lower temperature. The fluorescent data analysis demonstrated that a significantly higher level of fluorescent signal and hence higher sensitivity of detection is obtainable using our duplex probes in place of conventional TaqMan probes. Combined with real-time PCR instruments, the assay can be used to quantify the input target molecules and the dynamic linear range is of at least six orders of magnitude.
    New Journal of Chemistry 01/2003; 27(4):721-726. · 2.97 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: A novel method for the detection of specific nucleic acids in homogenous solution was developed. The method is based on the use of duplex probes in which fluorescent donor and quencher labeled on either oligonucleotide are held in close proximity, so that fluorescence is quenched. Amplification of the target sequence results in the cleavage of the probe and the resulting fluorescence can be detected. The fluorescent data analysis demonstrated that the duplex probes can specifically recognize the presence of target, and a significantly higher lever of relative fluorescent signal than TaqMan probes is obtainable. Combined with real-time PCR instruments, the assay can be used to quantify the input target molecules. As few as five copies of initial target molecules can be detected, and a large dynamic linear ranger (five orders of magnitude) is obtained.
    Analytica Chimica Acta 01/2003; · 4.39 Impact Factor
  • Source
    De-Ming Kong, Long Gu, Han-Xi Shen, Huai-Feng Mi
    [Show abstract] [Hide abstract]
    ABSTRACT: A modified molecular beacon that possesses a stem-hairpin structure as seen in conventional molecular beacons and can be cleaved during PCR in designed, and it can specifically recognize the presence of the target and was obviously more sensitive than conventional molecular beacons.
    Chemical Communications 05/2002; · 6.38 Impact Factor
  • De-Ming Kong, Long Gu, Han-Xi Shen, Huai-Feng Mi
    [Show abstract] [Hide abstract]
    ABSTRACT: A novel method for duplex probes is designed to simulate the TaqMan probe during polymerase chain reaction (PCR); two single-labelled probes are used for this method, which relies on the 5′-exonuclease activity of nucleic acid polymerase.
    Chemical Communications 01/2002; · 6.38 Impact Factor

Publication Stats

50 Citations
35.50 Total Impact Points

Institutions

  • 2002–2009
    • Nankai University
      • • Research Center for Analytical Sciences
      • • Institute of Polymer Chemistry
      • • Department of Chemistry
      Tianjin, Tianjin Shi, China