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具有核苷特异性的荧光猝灭技术在生物领域具有广泛应用.为了更好地理解这一过程的机理及其影响因素,研究了核苷对四甲基罗丹明(TMR)染料的分子间猝灭和在同一条寡聚核苷酸链中的分子内猝灭.与以前的研究结果一致,脱氧单磷酸鸟苷(dGMP)可以有效地猝灭TMR,而其他单磷酸腺苷对其的猝灭可以忽略.由斯特恩-沃尔默图获得TMR和dGMP的双分子猝灭常数为Ks=52.3L/mol.将TMR标记在寡聚核苷酸末端,可以观测到其荧光通过光致电子传递有效地被鸟苷猝灭,我们利用荧光相关光谱的方法测定了这一过程的猝灭速率常数.此外,所得的数据还显示鸟苷附近的碱基会对分子内的猝灭过程产生显著的位阻效应.这些结果将有助于设计寡聚核苷酸荧光探针和理解G猝灭过程.
Fluorescence quenching with nucleoside specificity has been widely used in the biological field.In order to better understand the mechanism of this process and its influencing factors, the intermolecular quenching of tetramethylrhodamine (TMR) Quenching and intramolecular quenching in the same oligonucleotide chain. Consistent with previous findings, dGMP can effectively quench TMR while its quenching by other adenosine monophosphate Off is negligible. The bimodal quenching constant of TMR and dGMP obtained by Stern-Walmer plot is Ks = 52.3 L / mol. The TMR is labeled at the end of the oligonucleotide and its fluorescence is observed to be photo-induced The electron transfer is effectively quenched by guanosine, and we determined the quenching rate constant for this process using fluorescence correlation spectroscopy. In addition, the data obtained show that bases near the guanosine give rise to intramolecular quenching processes Significant steric hindrance These results will help to design oligonucleotide fluorescent probes and to understand the G quenching process.