Ben Hlima Hajer, Dammak Mouna, Karray Aida, Drira Maroua, Michaud Philippe, Fendri Imen, Abdelkafi Slim
Laboratoire de Génie Enzymatique et de Microbiologie, Equipe de Biotechnologie des Algues, Ecole Nationale d'Ingénieurs de Sfax, Université de Sfax, Sfax 3038, Tunisia.
Laboratoire de Biochimie et de Génie Enzymatique des Lipases, Ecole Nationale d'Ingénieurs de Sfax, Université de Sfax, Sfax 3038, Tunisia.
Mar Drugs. 2021 Jan 28;19(2):70. doi: 10.3390/md19020070.
Microalgae have been poorly investigated for new-lipolytic enzymes of biotechnological interest. In silico study combining analysis of sequences homologies and bioinformatic tools allowed the identification and preliminary characterization of 14 putative lipases expressed by . These proteins have different molecular weights, subcellular localizations, low instability index range and at least 40% of sequence identity with other microalgal lipases. Sequence comparison indicated that the catalytic triad corresponded to residues Ser, Asp and His, with the nucleophilic residue Ser positioned within the consensus GXSXG pentapeptide. 3D models were generated using different approaches and templates and demonstrated that these putative enzymes share a similar core with common α/β hydrolases fold belonging to family 3 lipases and class GX. Six lipases were predicted to have a transmembrane domain and a lysosomal acid lipase was identified. A similar mammalian enzyme plays an important role in breaking down cholesteryl esters and triglycerides and its deficiency causes serious digestive problems in human. More structural insight would provide important information on the enzyme characteristics.
对于具有生物技术应用价值的新型脂肪分解酶，微藻尚未得到充分研究。通过结合序列同源性分析和生物信息学工具的计算机模拟研究，鉴定并初步表征了由[具体微藻名称未给出]表达的14种假定脂肪酶。这些蛋白质具有不同的分子量、亚细胞定位、低不稳定性指数范围，并且与其他微藻脂肪酶具有至少40%的序列同一性。序列比较表明，催化三联体对应于丝氨酸（Ser）、天冬氨酸（Asp）和组氨酸（His）残基，亲核残基丝氨酸位于共有序列GXSXG五肽内。使用不同的方法和模板生成了三维模型，结果表明这些假定的酶与属于第3家族脂肪酶和GX类的常见α/β水解酶折叠具有相似的核心结构。预测有六种脂肪酶具有跨膜结构域，并鉴定出一种溶酶体酸性脂肪酶。一种类似的哺乳动物酶在分解胆固醇酯和甘油三酯中起重要作用，其缺乏会导致人类严重的消化问题。更多的结构见解将为酶的特性提供重要信息。
