Roterman Irena, Slupina Mateusz, Stapor Katarzyna, Konieczny Leszek, Gądek Krzysztof, Nowakowski Piotr
Department of Bioinformatics and Telemedicine, Jagiellonian University-Medical College, Medyczna 7, 30-688 Krakow, Poland.
ALSTOM ZWUS Sp. z o.o., Modelarska 12, 40-142 Katowice, Poland.
ACS Omega. 2024 Aug 31;9(37):38506-38522. doi: 10.1021/acsomega.4c03658. eCollection 2024 Sep 17.
Repeated protein folding processes both in vivo and in vitro leading to the same structure for a specific amino acid sequence prove that the amino acid sequence determines protein structuring. This is also evidenced by the variability of structuring, dependent on the introduced mutations. An important phenomenon in this regard is the presence of a differentiated secondary structure for chain fragments of identical sequence representing distinct forms of the secondary-order structure. Proteins termed chameleon proteins contain polypeptide chain fragments of identical sequence (length 6-12 aa) showing structural differentiation: helix versus β-structure. In the present paper, it was shown that these fragments represent components matching the structural status dictated by the physicochemical properties of the entire structural unit. This structural matching is related to achieving the goal of the biological function of the structural unit. The corresponding secondary structure represents a means to achieving this goal, not an end in itself. A selected set of proteins from the ChSeq database have been analyzed using a fuzzy oil drop model (FOD-M) identifying the uniqueness of the hydrophobicity distribution taken as a medium for recording the specificity of a given protein and a given chameleon section in particular. It was shown that in the vast majority, the status of chameleon sections turns out to be comparable regardless of the represented secondary structure.
体内和体外反复进行的蛋白质折叠过程，使得特定氨基酸序列形成相同的结构，这证明氨基酸序列决定蛋白质的结构。结构的可变性也证明了这一点，这种可变性取决于引入的突变。在这方面，一个重要的现象是，相同序列的链片段存在不同的二级结构，代表着不同形式的二级结构。被称为变色龙蛋白的蛋白质含有相同序列（长度为6 - 12个氨基酸）的多肽链片段，呈现出结构差异：螺旋结构与β结构。在本文中，研究表明这些片段代表与整个结构单元的物理化学性质所决定的结构状态相匹配的组分。这种结构匹配与实现结构单元的生物学功能目标相关。相应的二级结构是实现这一目标的一种手段，而不是目的本身。使用模糊油滴模型（FOD - M）对从ChSeq数据库中选取的一组蛋白质进行了分析，该模型将疏水性分布的独特性作为记录给定蛋白质，特别是给定变色龙片段特异性的介质。结果表明，在绝大多数情况下，无论呈现何种二级结构，变色龙片段的状态都是可比的。
