跳至主要内容

A colorimetric strategy for assay of protease activity based on gold nanoparticle growth controlled by ascorbic acid and Cu(II)-coordinated peptide

Author：Lin Liu, Dehua Deng, Yiru Wang, Kewei Song, Ziling Shang, Qiao Wang, Ning Xia, Bing Zhang   《Sensors and Actuators B: Chemical》

ABSTRACTS
We developed a colorimetric method for assay of protease activity through the growth of gold nanoparticles (AuNPs) with ascorbic acid (AA) as the reducing agent. The method is based on the difference in the catalytic activity of various Cu2+ species toward AA oxidation. A mutational peptide is employed as the protease substrate, in which only one amino acid residue is replaced by the histidine residue. Specifically, HAuCl4 can be reduced into AuNPs by AA; Cu2+ ion promotes the oxidation of AA under oxygen atmosphere by a redox cycling, thus preventing the formation of AuNPs. Cleavage of the substrate peptide results in the exposure of an amino terminal Cu2+and Ni2+-binding (ATCUN) motif in the NH2-terminus of one fragment. The resultant ATCUN peptide can sequestrate Cu2+ and thus depress the catalytic oxidation of AA. The consumption of AA is monitored by UV–vis spectra and differential pulse voltammetry. The high extinction coefficient of the generated AuNPs enables the quantitative and sensitive colorimetric analysis of protease. To demonstrate the analytical performances, β-secretase was tested as a model protease. By employing peptide-functionalized magnetic beads, β-secretase in serum was determined with a satisfactory result. This work provides valuable information for designing of novel protease biosensors.
    KEY WORDS
    Protease
    ATCUN motif
    Gold nanoparticles
    Copper ion
    Ascorbic acid
    Beta-secretase
    SCREENSHOT

    RELATED PRODUCTS
    Peptides
    CHAINING
    https://www.sciencedirect.com/science/article/pii/S0925400518306142
    标签：

    评论

    发表评论

    此博客中的热门博文

    CAS:85466-18-8|Thymopoietin II (32-35)|RKDV

    Contact： Liven Qian(钱叶华)-Custom Peptide Mobile: 13761298676（微信） Email：cps037@chinapeptides.net QQ：2880526724 ChinaPeptides Co., Ltd./强耀生物科技有限公司 Name Thymopoietin II (32-35) Code [85466-18-8] The alias Thymopoietin II (32-35) Sequence (single letter abbreviation) RKDV Sequence (three-letter abbreviation) H-Arg-Lys-Asp-Val-OH (trifluoroacetate salt) A basic description TP-4 and TP-3; shortest active thymopoietin II fragments described that exhibit potent immunoregulatory properties in vitro and in vivo. solubility The molecular weight 516.6 Chemical formula C21H40N8O7 The purity 80%，90%，95%，98%，99% Weight 1mg,5mg,10mg,50mg,100mg,1g Storage conditions Store at -20°C. Keep tightly closed. Store in a cool dry place. Number of Residues: 4 1-Letter Code: RKDV 3-Letter Code: Arg-Lys-Asp-Val Molecular weight (Mr): 516.6 g/mol Isoelectric point: 10.1 Net charge at pH 7.0: 1.0 Average hydrophilicity: 1.9 Ratio of hydrophilic residues / total number of residues...
    1 条评论
    阅读全文

    β-Amyloid (1-42), human|DAEFRHDSGYEVHHQKLVFFAEDVGSNKGAIIGLMVGGVVIA

    Contact： Liven Qian(钱叶华)-Custom Peptide Mobile: 13761298676（微信） Email：cps037@chinapeptides.net QQ：2880526724 ChinaPeptides Co., Ltd./强耀生物科技有限公司   04010011526 β-Amyloid (1-42), human DAEFRHDSGYEVHHQKLVFFAEDV GSNKGAIIGLMVGGVVIA Number of Residues: 42 1-Letter Code: DAEFRHDSGYEVHHQKLVFFAEDVGSNKGAIIGLMVGGVVIA 3-Letter Code: Asp-Ala-Glu-Phe-Arg-His-Asp-Ser-Gly-Tyr-Glu-Val-His-His-Gln-Lys-Leu-Val-Phe-Phe-Ala-Glu-Asp-Val-Gly-Ser-Asn-Lys-Gly-Ala-Ile-Ile-Gly-Leu-Met-Val-Gly-Gly-Val-Val-Ile-Ala Molecular weight (Mr): 4513.12 g/mol Isoelectric point: 5.8 Net charge at pH 7.0: -1.7 Average hydrophilicity: -0.1 Ratio of hydrophilic residues / total number of residues: 31 %    Name beta-Amyloid (1-42), recombinant Code   The alias beta-Amyloid (1-42), recombinant Sequence (single letter abbreviation) DAEFRHDSGYEVHHQKLVFFAEDVGSNKGAIIGLMVGGVVIA Sequence (three-letter abbreviation) H-Asp-Ala-Glu-Phe-Arg-His-Asp-Ser-Gly-Tyr-Glu-Val-...
    发表评论
    阅读全文

    The therapeutic effect of anti-CD52 treatment in murine experimental autoimmune encephalomyelitis is associated with altered IL-33 and ST2 expression levels

    文献作者：Mark Barbour, Rachel Wood, Shehla U.Hridi, Chelsey Wilson, Grant McKay, Trevor J.Bushell, Hui-Rong Jiang   《Journal of Neuroimmunology》 ABSTRACTS Experimental autoimmune encephalomyelitis  (EAE) mice were administered with murine anti-CD52  antibody  to investigate its therapeutic effect and whether the treatment modulates IL-33 and ST2 expression. EAE severity and  central nervous system  (CNS) inflammation were reduced following the treatment, which was accompanied by peripheral  T and B lymphocyte  depletion and reduced production of various  cytokines  including IL-33, while sST2 was increased. In spinal cords of EAE mice, while the number of IL-33 +  cells remained unchanged, the extracellular level of IL-33 protein was significantly reduced in anti-CD52 antibody treated mice compared with controls. Furthermore the number of ST2 +  cells in the spinal cord of treated EAE mice was  downregulated ...
    发表评论
    阅读全文