法国波尔多大学Antoine Loquet研究团队近日取得一项新成果。经过不懈努力，他们提出了用原位魔角自旋核磁共振技术对被包被病原体细胞壁和荚膜多糖的分子鉴别。2025年2月16日出版的《美国化学会杂志》发表了这项成果。

该课题组研究人员研究了魔角旋转（MAS）固态核磁共振技术如何提高分析能力，以表征这种封装病原体的结构和动力学。质子检测实验、基于动态的过滤器和弛豫测量的多功能性有助于将C. neoformans的高度移动的外囊结构与内部刚性细胞壁区分开来。此外，课题组研究人员报道了基于核磁共振动态过滤器的脂滴甘油三酯分子的原位检测。总之，该研究团队展示了一种非破坏性技术来研究包封微生物的细胞壁结构，以新形式c为模型，一种空气传播的机会性真菌病原体，主要感染免疫功能低下的宿主，但也感染有能力的宿主。

据悉，致病性真菌和细菌细胞被细胞壁包裹着，细胞壁是细胞表面的分子屏障，是一个在发病过程中不断进化的关键结构。了解构成这种细胞包膜的多糖的分子组成、结构组织和流动性对于将细胞壁组织与其致病性联系起来以及识别潜在的抗真菌靶点至关重要。对于真菌病原体新形态隐球菌，由于存在额外的外部多糖荚膜壳，细胞包膜的表征变得复杂。

附：英文原文

Title: Molecular Distinction of Cell Wall and Capsular Polysaccharides in Encapsulated Pathogens by In Situ Magic-Angle Spinning NMR Techniques

Author: Alons Lends, Gaelle Lamon, Loic Delcourte, Aude Sturny-Leclere, Axelle Grélard, Estelle Morvan, Muhammed Bilal Abdul-Shukkoor, Mélanie Berbon, Alicia Vallet, Birgit Habenstein, Erick J. Dufourc, Paul Schanda, Vishukumar Aimanianda, Antoine Loquet

Issue&Volume: February 16, 2025

Abstract: Pathogenic fungal and bacterial cells are enveloped within a cell wall, a molecular barrier at their cell surface, and a critical architecture that constantly evolves during pathogenesis. Understanding the molecular composition, structural organization, and mobility of polysaccharides constituting this cell envelope is crucial to correlate cell wall organization with its role in pathogenicity and to identify potential antifungal targets. For the fungal pathogen Cryptococcus neoformans, the characterization of the cell envelope has been complexified by the presence of an additional external polysaccharide capsular shell. Here, we investigate how magic-angle spinning (MAS) solid-state NMR techniques increase the analytical capabilities to characterize the structure and dynamics of this encapsulated pathogen. The versatility of proton detection experiments, dynamic-based filters, and relaxation measurements facilitate the discrimination of the highly mobile external capsular structure from the internal rigid cell wall of C. neoformans. In addition, we report the in situ detection of triglyceride molecules from lipid droplets based on NMR dynamic filters. Together, we demonstrate a nondestructive technique to study the cell wall architecture of encapsulated microbes using C. neoformans as a model, an airborne opportunistic fungal pathogen that infects mainly immunocompromised but also competent hosts.

DOI: 10.1021/jacs.4c16975

Source: https://pubs.acs.org/doi/abs/10.1021/jacs.4c16975