College of Food Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
College of Food Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; Key Laboratory of Environment Correlative Dietology (Huazhong Agricultural University), Ministry of Education, Wuhan 430070, China; Wuhan Engineering Research Center of Bee Products on Quality and Safety Control, Wuhan 430070, China.
Int J Biol Macromol. 2018 Oct 15;118(Pt A):1136-1141. doi: 10.1016/j.ijbiomac.2018.06.189. Epub 2018 Jul 3.
As one of receptors of the acquired membrane, human salivary α‑amylase (HSA) plays an important role in the formation of caries. In vitro conditions, sorghum procyanidins (SPC) tetramer has a better inhibitory effect on the adhesion of Streptococcus mutans to hydroxyapatite than SPC-dimer and SPC-trimer. This study investigated the interaction mechanism between HSA and SPC-tetramer using spectroscopic techniques including fluorescence, UV-vis absorption, and circular dichroism (CD). Fluorescence data revealed that the fluorescence quenching of HSA by SPC-tetramer was a static quenching process, and that the SPC-tetramer was bound with HSA at the ratio of 1:1 in SPC-tetramer-protein complex. Meanwhile, the analysis of CD demonstrated that the conformation of HSA was altered in the presence of SPC-tetramer. The conformation changes of HSA might contribute to the reduction of the adhesion of cariogenic bacteria and finally decrease the occurrence of dental caries.
作为获得性膜的受体之一，人唾液α-淀粉酶（HSA）在龋齿的形成中起着重要作用。在体外条件下，高粱原花青素四聚体对变形链球菌黏附羟基磷灰石的抑制作用优于二聚体和三聚体。本研究采用荧光、紫外-可见吸收和圆二色性（CD）等光谱技术研究了 HSA 与 SPC-四聚体的相互作用机制。荧光数据表明，SPC-四聚体对 HSA 的荧光猝灭是一个静态猝灭过程，并且在 SPC-四聚体-蛋白质复合物中，SPC-四聚体与 HSA 以 1:1 的比例结合。同时，CD 分析表明，SPC-四聚体的存在改变了 HSA 的构象。HSA 构象的变化可能有助于减少致龋菌的黏附，最终减少龋齿的发生。
