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核酸是重要的生命物质,对核酸序列的选择性切割是当前基因工程的关键问题.在生理条件及非酶存在下,核酸非常稳定(磷酸二酯键在pH 7,25℃时的半衰期为2亿年,因此,近年来研究的人工酶是通过氧化脱氧核糖来切断DNA的,而有关选择性水解断裂核酸的报道则很少,主要困难是缺乏高效的“分子剪刀”,有关稀土对核酸断裂的研究报道尚不多见.作者曾报道了除Ce(Ⅳ)外,其他稀土对5’-腺嘌呤核苷酸(5’-AMP)及5’-鸟嘌呤核苷酸(5’-GMP)均无明显水解作用,并且过去报道的体系为碱性介质,此时稀土以氢氧化物沉淀形式存在为非均相体系,其应用局限性非常大,因此,寻求可溶性的稀土水解核酸体系就显得非常重要.本文用核磁共振(NMR)和化学法研究了Yb-Ge-132和Pr-Ge-132配合物对5’-AMP及5’-dAMP的断裂作用,指出Yb-Ge-132和Pr-Ge-132使5’-AMP水解为腺苷(A)及无机磷,使5’-dAMP水解为脱氧腺苷(dA)及无机磷,其断裂机制为水解断裂,这对于研究稀土与核酸的作用,寻找新的核酸均相水解体系都具有非常重要的意义.
Nucleic acids are important life-forms, and the selective cleavage of nucleic acid sequences is a key issue in current genetic engineering, and the nucleic acids are very stable in physiological conditions and in the absence of enzymes (phosphodiester bonds have a half-life of 2 at pH 7,25 ° C Therefore, the artificial enzyme studied in recent years is to cut DNA by oxidizing deoxyribose. However, there are few reports on selective hydrolytic cleavage of nucleic acid. The main difficulty is the lack of efficient “molecular scissors” Of the reports are not yet available.It has been reported in addition to Ce (Ⅳ), other rare earth 5’- adenine nucleotide (5’-AMP) and 5’-guanine nucleotide (5’-GMP ) Have no significant hydrolysis, and the system reported in the past as an alkaline medium, the presence of rare earth hydroxide precipitation form heterogeneous system, its application is very limited, therefore, to find a soluble rare earth hydrolysis of nucleic acid system Which is very important.In this paper, the cleavage of 5’-AMP and 5’-dAMP by Yb-Ge-132 and Pr-Ge-132 complexes was studied by NMR and chemical methods, Pr-Ge-132 hydrolyzes 5’-AMP to adenosine (A) and inorganic phosphorus to hydrolyze 5’-dAMP to The mechanism of the cleavage of oxygen adenosine (dA) and inorganic phosphorus is hydrolytic cleavage, which is very important for studying the effect of rare earth and nucleic acid and searching for a new homogeneous nucleic acid hydrolysis system.