Fruit bromelain is a cysteine protease accumulated in pineapple fruits. This proteolytic enzyme has received high demand for industrial and therapeutic applications. In this study, fruit bromelain sequences QIM61759, QIM61760 and QIM61761 were retrieved from the National Center for Biotechnology Information (NCBI) Genbank Database. The tertiary structure of fruit bromelain QIM61759, QIM61760 and QIM61761 was generated by using MODELLER. The result revealed that the local stereochemical quality of the generated models was improved by using multiple templates during modelling process. Moreover, by comparing with the available papain model, structural analysis provides an insight on how pro-peptide functions as a scaffold in fruit bromelain folding and contributing to inactivation of mature protein. The structural analysis also disclosed the similarities and differences between these models. Lastly, thermal stability of fruit bromelain was studied. Molecular dynamics simulation of fruit bromelain structures at several selected temperatures demonstrated how fruit bromelain responds to elevation of temperature.

中文翻译：

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水果菠萝蛋白酶的比较建模研究，使用分子动力学模拟。

水果菠萝蛋白酶是菠萝果实中积累的半胱氨酸蛋白酶。这种蛋白水解酶已经在工业和治疗应用中获得了很高的需求。在这项研究中，水果菠萝蛋白酶序列QIM61759，QIM61760和QIM61761从国家生物技术信息中心（NCBI）Genbank数据库中检索。水果菠萝蛋白酶QIM61759，QIM61760和QIM61761的三级结构是使用MODELLER生成的。结果表明，在建模过程中使用多个模板可以提高生成模型的局部立体化学质量。此外，通过与可用的木瓜蛋白酶模型进行比较，结构分析提供了关于前肽如何在水果菠萝蛋白酶折叠中充当支架并有助于成熟蛋白质失活的见解。结构分析还揭示了这些模型之间的异同。最后，研究了水果菠萝蛋白酶的热稳定性。在几个选定的温度下水果菠萝蛋白酶结构的分子动力学模拟证明了水果菠萝蛋白酶如何响应温度升高。