Gold nanoparticle sensor for homocysteine thiolactone-induced protein modification.
Gold nanoparticle sensor for homocysteine thiolactone-induced protein modification.
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DOI：
10.1021/la7033142
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发表时间：
2008-04
期刊：
影响因子：
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通讯作者：
A. Gates;S. O. Fakayode;M. Lowry;G. Ganea;Abitha Murugeshu;J. W. Robinson;R. Strongin;I. Warner
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文献类型：
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作者：
A. Gates;S. O. Fakayode;M. Lowry;G. Ganea;Abitha Murugeshu;J. W. Robinson;R. Strongin;I. Warner
同型半胱氨酸硫代内酯诱导的蛋白质修饰（Homocysteine thiolactone-induced protein modification，HTPM）是一种独特的翻译后蛋白质修饰，被认为是心血管疾病的重要生物标志物。HTPM涉及高半胱氨酸硫代内酯（HTL）在赖氨酸残基处对蛋白质进行位点特异性酰化，以产生蛋白质高半胱氨酸酰胺，已在冠心病患者中发现高半胱氨酸酰胺水平升高。在此，我们报告了一种新的纳米金（GNP）生化传感器的发展，用于检测蛋白同型半胱氨酸在体外血清蛋白为基础的模型系统。将人血清白蛋白（HSA）和人血清在体外进行HTPM，以分别产生HSA-同型半胱氨酸或血清蛋白同型半胱氨酸，随后用柠檬酸盐封端的GNP处理。该GNP传感器通常在蛋白质模型系统中提供HTPM的瞬时视觉确认。GNP在HSA-同型半胱氨酸存在下的透射电子显微镜图像表明，修饰导向的纳米颗粒组装是生化传感器产生比色信号的机制。所得的纳米颗粒-蛋白质组装体表现出优异的热稳定性和稀释稳定性，这是预期的化学吸附和分子间二硫键稳定的系统。该传感器通常对大于约5 mg/mL的改性人血清浓度提供线性响应。该方法在人血清中的计算检测限和校准灵敏度分别为5.2 mg/mL和13.6 Au。（μ g/mL）-1。
Homocysteine thiolactone-induced protein modification (HTPM) is a unique post-translational protein modification that is recognized as an emergent biomarker for cardiovascular disease. HTPM involves the site-specific acylation of proteins at lysine residues by homocysteine thiolactone (HTL) to produce protein homocystamide, which has been found at elevated levels in patients with coronary heart disease. Herein, we report the development of a novel gold nanoparticle (GNP) biochemical sensor for detection of protein homocystamide in an in vitro serum protein-based model system. Human serum albumin (HSA) and human sera were subjected to HTPM in vitro to produce HSA-homocystamide or serum protein homocystamide, respectively, which was subsequently treated with citrate-capped GNPs. This GNP sensor typically provided instantaneous visual confirmation of HTPM in the protein model systems. Transmission electron microscopy images of the GNPs in the presence of HSA-homocystamide suggest that modification-directed nanoparticle assembly is the mechanism by which the biochemical sensor produces a colorimetric signal. The resultant nanoparticle-protein assembly exhibited excellent thermal and dilutional stability, which is expected for a system stabilized by chemisorption and intermolecular disulfide bonding. The sensor typically provided a linear response for modified human sera concentrations greater than approximately 5 mg/mL. The calculated limit of detection and calibration sensitivity for the method in human sera were 5.2 mg/mL and 13.6 AU . (microg/mL)-1, respectively.