Chitosan is a structurally diverse biopolymer that is commercially derived from chitin by chemical processing, but chitin deacetylases (CDAs) potentially offer a sustainable and more controllable approach allowing the production of chitosans with tailored structures and biological activities. We investigated the CDA from Podospora anserina (PaCDA) which is closely related to Colletotrichum lindemuthianum CDA in the catalytic domain, but unique in having two chitin-binding domains. We produced recombinant PaCDA in Hansenula polymorpha for biochemical characterization and found that the catalytic domain of PaCDA is also functionally similar to C. lindemuthianum CDA, though differing in detail. When studying the enzyme’s mode of action on chitin oligomers by quantitative mass-spectrometric sequencing, we found almost all possible sequences up to full deacetylation but with a clear preference for specific products. Deletion muteins lacking one or both CBDs confirmed their proposed function in supporting the enzymatic conversion of the insoluble substrate colloidal chitin.

壳聚糖是一种结构多样的生物聚合物，可通过化学加工从几丁质中商业获得，但是几丁质脱乙酰基酶（CDA）可能提供一种可持续且更可控制的方法，从而可生产具有定制结构和生物活性的壳聚糖。我们研究了来自中华灰猪（的CDA （PaCDA），该CDA在催化域中与Colletotrichum lindemuthianum CDA密切相关，但在具有两个几丁质结合域中却是独特的。我们在多形汉逊酵母中生产了重组PaCDA，用于生化鉴定，发现PaCDA的催化结构域在功能上也与C. lindemuthianum相似。CDA，尽管在细节上有所不同。当通过定量质谱测序研究酶对几丁质低聚物的作用方式时，我们发现直至完全脱乙酰化为止几乎所有可能的序列，但明确偏爱特定产物。缺少一个或两个CBD的缺失突变蛋白证实了它们在支持不溶性底物胶体几丁质的酶促转化方面的拟议功能。