Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Moscow region, Russia.
Institute of Protein Research, Russian Academy of Sciences, Pushchino, Moscow Region, Russia.
Bull Exp Biol Med. 2024 Aug;177(4):454-459. doi: 10.1007/s10517-024-06207-8. Epub 2024 Sep 12.
Small-angle X-ray scattering (SAXS) and Fourier transform infrared (FTIR) spectroscopy were used to investigate structural peculiarities of two types of amyloid aggregates of smooth muscle titin, which differed in their morphology and ability to disaggregate, and differently bound thioflavin T dye. SAXS showed that the structure/shape of the two titin aggregate types was close to a flat shape. FTIR spectroscopy revealed no differences in the secondary structure of the two types. These data suggest that both types of "flat-shape" titin aggregates are identical in their secondary structure and, as shown previously, have a quaternary cross-β structure. An assumption was made that the most stable supramolecular complexes of a cross-β structure, which do not differ in their secondary structure, formed first during the aggregation of smooth muscle titin. Then, depending on ambient conditions, these supramolecular structures could form titin aggregates of different morphology and properties.
小角 X 射线散射（SAXS）和傅里叶变换红外（FTIR）光谱用于研究两种不同形态和去聚集能力、以及不同结合硫黄素 T 染料的平滑肌肌联蛋白的淀粉样纤维聚集体的结构特征。SAXS 表明，两种肌联蛋白聚集体的结构/形状接近扁平形状。FTIR 光谱未显示两种类型的二级结构有差异。这些数据表明，两种“扁平形状”的肌联蛋白聚集体在二级结构上是相同的，并且如先前所示，具有四级交叉-β结构。假设在平滑肌肌联蛋白聚集过程中，首先形成具有相同二级结构但不具有不同二级结构的最稳定的交叉-β结构超分子复合物。然后，根据环境条件，这些超分子结构可以形成具有不同形态和性质的肌联蛋白聚集体。
