Detection of Key Proteins in Obstetric Preeclampsia by Nanocomposites Using Gold Nanoparticles/ DNA/Methylene Blue

Abstract

As a nuclear transcription factor, cAMP response element-binding protein (CREB) can be used in gene transcription regulation, apoptosis regulation, immune response and other life activities. However, the biological characteristics of CREB are controlled by its phosphorylation level. The surface of gold electrode is modified by DNA sequence of capture probe containing specific and high affinity binding sites of CREB. Then, the methylene blue (MB) solution is added into the gold nanoparticle/DNA complex. The composite nanomaterials, namely gold nanoparticles/DNA/MB, are obtained by inserting MB into DNA molecules. The nanomaterials are used as signal markers, and the phosphorylation sites are specifically labeled by Zr4+-mediated nanocomposite beacons. It is used to detect the phosphorylation level of CREB in placenta of preeclampsia pregnant women. In the experiment, the phosphorylated CREB can be fully modified on the surface of gold nanoprobe electrode after incubating for 130 min. The optimal incubation time between nanocomposite beacon and targeted protein electrode is 60 min. Based on this method, the development trend of CREB phosphorylation level is obtained. Comparing the phosphorylation level of CREB in preeclampsia pregnant women and normal pregnant women, it can be seen that the phosphorylation level of CREB in preeclampsia pregnant women is significantly increased. The designed nanocomposites have good sensitivity and specificity for the phosphorylation level of CREB, which can help to analyze and study the protein phosphorylation level of patients under physiological and pathological conditions.