Dayrit Geraldine B, Burigsay Normela Patricia F, Vera Cruz Emmanuel M, Santos Mudjekeewis D
The Graduate School, University of Santo Tomas, España Boulevard, Manila, 1015, Philippines.
College of Public Health, University of the Philippines Manila, Ermita, Manila, 1000, Philippines.
Heliyon. 2024 Jun 8;10(12):e32748. doi: 10.1016/j.heliyon.2024.e32748. eCollection 2024 Jun 30.
The molecular chaperone heat shock proteins 70 (Hsp70) play a pivotal role in preserving cellular integrity and managing stress. This study extensively examined two Hsp70 proteins, -Hsp70cBi, inducible, and -Hsp70cBc, constitutively expressed, in Nile tilapia () utilizing in silico analysis, homology modeling, and functional annotation. Employing the SWISS-MODEL program for homology modeling, the proposed models underwent thorough reliability assessment via ProSA, Verify 3D, PROVE, ERRAT, and Ramachandran plot analyses. Key features of On-Hsp70cBi and On-Hsp70cBc included amino acid lengths (640 and 645) and molecular weights (70,233.48 and 70,773.17 Da). Moreover, theoretical isoelectric points (pI = 5.63 and 5.28), indicated their acidic nature. Counts of negatively and positively charged residues (95 and 86; 95 and 81) revealed neutrality, while instability index (II) values of 35.27 (-Hsp70cBi) and 38.85 (-Hsp70cBc) suggested stability. Aliphatic index (AI) values were notably high for both proteins (84.58 and 82.85), indicating stability across a broad temperature range. Domain architecture analysis showed both proteins to contain an MreB/Mbl domain. Protein-protein interaction analysis identified the co-chaperone Stip1 as a primary functional partner. Comparative modeling yielded highly reliable 3D models, showcasing structural similarity to known proteins and predicted binding sites. Additionally, both proteins are primarily localized in the cytoplasm. Functional analysis predicted an AMP-PNP binding site for -Hsp70cBi and an ATP binding site for -Hsp70cBc. These findings deepened our understanding of Hsp70cBc and Hsp70cBi in Nile tilapia, underscoring their significance in fish physiology and warranting further investigation, thus advancing our knowledge of these proteins' roles in cellular processes and stress responses, potentially impacting fish health and resilience.
分子伴侣热休克蛋白70（Hsp70）在维持细胞完整性和应对应激方面发挥着关键作用。本研究利用计算机分析、同源建模和功能注释，对尼罗罗非鱼（）中的两种Hsp70蛋白——诱导型的Hsp70cBi和组成型表达的Hsp70cBc进行了广泛研究。使用SWISS-MODEL程序进行同源建模，通过ProSA、Verify 3D、PROVE、ERRAT和拉氏图分析对所提出的模型进行了全面的可靠性评估。尼罗罗非鱼Hsp70cBi和Hsp70cBc的关键特征包括氨基酸长度（分别为640和645）和分子量（分别为70,233.48和70,773.17道尔顿）。此外，理论等电点（pI分别为5.63和5.28）表明它们呈酸性。带负电荷和正电荷残基的数量（分别为95和86；95和81）显示为中性，而不稳定指数（II）值分别为35.27（Hsp70cBi）和38.85（Hsp70cBc）表明具有稳定性。两种蛋白质的脂肪族指数（AI）值都很高（分别为84.58和82.85），表明在广泛的温度范围内都具有稳定性。结构域分析表明这两种蛋白质都含有一个MreB/Mbl结构域。蛋白质-蛋白质相互作用分析确定共伴侣蛋白Stip1为主要功能伙伴。比较建模产生了高度可靠的三维模型，展示了与已知蛋白质的结构相似性和预测的结合位点。此外，这两种蛋白质主要定位于细胞质中。功能分析预测Hsp70cBi有一个AMP-PNP结合位点，Hsp70cBc有一个ATP结合位点。这些发现加深了我们对尼罗罗非鱼中Hsp70cBc和Hsp70cBi的理解，强调了它们在鱼类生理学中的重要性，值得进一步研究，从而推进我们对这些蛋白质在细胞过程和应激反应中作用的认识，可能会影响鱼类健康和恢复力。
