Institute for Biology and Biotechnology of Plants , University of Muenster , Schlossplatz 8 , 48143 Münster , Germany.
Laboratoire Ingénierie des Matériaux Polymères (IMP), CNRS UMR 5223 , Université Lyon, Université Claude Bernard Lyon 1 , 15 bd A Latarjet , 69622 Villeurbanne , France.
J Am Chem Soc. 2019 Feb 20;141(7):3137-3145. doi: 10.1021/jacs.8b12561. Epub 2019 Feb 8.
Chitosans, a family of ß-(1,4)-linked, partially N-acetylated polyglucosamines, are considered to be among the most versatile and most promising functional biopolymers. Chemical analysis and bioactivity studies revealed that the functionalities of chitosans strongly depend on the polymers' degree of polymerization and fraction of acetylation. More recently, the pattern of acetylation ( P) has been proposed as another important parameter to influence functionalities of chitosans. We therefore carried out studies on the acetylation pattern of chitosan polymers produced by three recombinant fungal chitin deacetylases (CDAs) originating from different species, namely, Podospora anserina, Puccinia graminis f. sp. tritici, and Pestalotiopsis sp. We analyzed the chitosans by H NMR, C NMR, and SEC-MALS and established new methods for P analysis based on enzymatic mass spectrometric fingerprinting and in silico simulations. Our studies strongly indicate that the different CDAs indeed produce chitosans with different P. Finally, Zimm plot analysis revealed that enzymatically treated polymers differ with respect to their second virial coefficient and radius of gyration indicating an influence of P on polymer-solvent interactions.
壳聚糖是一类β-(1,4)-连接的、部分 N-乙酰化的多糖，被认为是用途最广泛、最有前途的功能生物聚合物之一。化学分析和生物活性研究表明，壳聚糖的功能强烈依赖于聚合物的聚合度和乙酰化分数。最近，人们提出了乙酰化模式（P）作为另一个影响壳聚糖功能的重要参数。因此，我们对三种来源于不同物种的重组真菌几丁质脱乙酰酶（CDA）产生的壳聚糖聚合物的乙酰化模式进行了研究，这三种物种分别是：灰盖鬼伞、禾柄锈菌小麦专化型和拟盘多毛孢。我们通过 H NMR、C NMR 和 SEC-MALS 对壳聚糖进行了分析，并基于酶质谱指纹图谱和计算机模拟建立了新的 P 分析方法。我们的研究强烈表明，不同的 CDA 确实产生了具有不同 P 的壳聚糖。最后，Zimm 图分析表明，酶处理后的聚合物在第二维里系数和回转半径方面存在差异，这表明 P 对聚合物-溶剂相互作用有影响。
