Phukan Homen, Sarma Abhijit, Rex Devasahayam Arokia Balaya, Rai Akhila Balakrishna, Prasad Thottethodi Subrahmanya Keshava, Madanan Madathiparambil Gopalakrishnan
ICMR-Regional Medical Research Centre, Port Blair 744103, Andaman and Nicobar Islands, India.
Center for Systems Biology and Molecular Medicine, Yenepoya Research Centre, Yenepoya (Deemed to be University), Mangaluru 575018, Karnataka, India.
ACS Omega. 2022 May 25;7(22):18569-18576. doi: 10.1021/acsomega.2c01245. eCollection 2022 Jun 7.
Posttranslational modifications (PTMs) are decisive factors in the structure, function, and localization of proteins in prokaryotic and eukaryotic organisms. However, prokaryotic organisms lack subcellular organelles, and protein localization based on subcellular locations like cytoplasm, inner membrane, periplasm, and outer membrane can be accounted for functional characterization. We have identified 131 acetylated, 1182 citrullinated, 72 glutarylated, 5 palmitoylated, and 139 phosphorylated proteins from Triton X-114 fractionated proteins of , the pathogen of re-emerging zoonotic disease leptospirosis. In total, 74.7% of proteins were found exclusively in different Triton X-114 fractions. Additionally, 21.9% of proteins in multiple fractions had one or more PTM specific to different Triton X-114 fractions. Altogether, 96.6% of proteins showed exclusiveness to different Triton X-114 fractions either due to the presence of the entire protein or with a specific PTM type or position. Further, the PTM distribution within Triton X-114 fractions showed higher acetylation in aqueous, glutarylation in detergent, phosphorylation in pellet, and citrullination in wash fractions representing cytoplasmic, outer membrane, inner membrane, and extracellular locations, respectively. Identification of PTMs in proteins with respect to the subcellular localization will help to characterize candidate proteins before developing novel drugs and vaccines rationally to combat leptospirosis.
翻译后修饰（PTMs）是原核生物和真核生物中蛋白质结构、功能及定位的决定性因素。然而，原核生物缺乏亚细胞器，基于细胞质、内膜、周质和外膜等亚细胞位置的蛋白质定位可用于功能表征。我们从再次出现的人畜共患病钩端螺旋体病的病原体——问号钩端螺旋体的Triton X - 114分级分离蛋白中鉴定出了131种乙酰化蛋白、1182种瓜氨酸化蛋白、72种戊二酰化蛋白、5种棕榈酰化蛋白和139种磷酸化蛋白。总共发现74.7%的蛋白仅存在于不同的Triton X - 114分级分离组分中。此外，多个组分中的21.9%的蛋白具有一种或多种特定于不同Triton X - 114分级分离组分的翻译后修饰。总体而言，96.6%的蛋白因其完整蛋白的存在或特定的翻译后修饰类型或位置而在不同的Triton X - 114分级分离组分中具有排他性。此外，Triton X - 114分级分离组分内的翻译后修饰分布显示，水相中的乙酰化程度较高、去污剂相中的戊二酰化程度较高、沉淀中的磷酸化程度较高以及洗涤组分中的瓜氨酸化程度较高，分别代表细胞质、外膜、内膜和细胞外位置。关于亚细胞定位鉴定蛋白质中的翻译后修饰将有助于在合理开发新型药物和疫苗以对抗钩端螺旋体病之前对候选蛋白质进行表征。
