A.N. Bach Institute of Biochemistry, Federal Research Centre 'Fundamentals of Biotechnology' of the Russian Academy of Sciences, Moscow, Russia.
N.D. Zelinsky Institute of Organic Chemistry Russian Academy of Sciences, Moscow, Russia.
Biochem Biophys Res Commun. 2024 Nov 5;732:150419. doi: 10.1016/j.bbrc.2024.150419. Epub 2024 Jul 17.
To enhance the photoconversion performance of biphotochromic moxSAASoti protein, a substitution F97 M was introduced. In addition to enhancing the target properties, this substitution also resulted in the crystallization of the recombinant protein within living HeLa cells (also referred to as in cellulo crystallization). The phenomenon of protein crystallization in living cells is not unique, yet the mechanisms and application of in cellulo crystallization remain significant for further research. However, in cellulo crystallization is atypical for fluorescent proteins and detrimental for their biotechnological application. The objective of this study was to elucidate the underlying mechanisms responsible for the crystallization of moxSAASotiin cellulo. For this purpose, the crystal structure of the green form of biphotochromic protein moxSAASoti was determined at high resolution, which surprisingly has a space group, different from those of parent mSAASoti. The analysis provided allowed to propose a mechanism of new crystal contacts formation, which might be a cause of in cellulo protein crystallization.
为了提高双光色 moxSAASoti 蛋白的光致变色性能，引入了 F97M 取代。除了增强目标特性外，这种取代还导致重组蛋白在活 HeLa 细胞内结晶（也称为细胞内结晶）。活细胞中蛋白质结晶的现象并不罕见，但细胞内结晶的机制和应用对于进一步研究仍然具有重要意义。然而，对于荧光蛋白来说，细胞内结晶是非典型的，并且对其生物技术应用有害。本研究的目的是阐明 moxSAASoti 在细胞内结晶的潜在机制。为此，高分辨率测定了双光色蛋白 moxSAASoti 的绿光形式的晶体结构，令人惊讶的是，它的空间群与母本 mSAASoti 的不同。分析结果提出了形成新晶体接触的机制，这可能是细胞内蛋白质结晶的原因。
