Brucellaceae are Gram-negative bacteria that cause brucellosis, one of the most distributed worldwide zoonosis, transmitted to humans by contact with either infected animals or their products. The lipopolysaccharide exposed on the cell surface has been intensively studied and is considered a major virulence factor of Brucella. In the last years, structural studies allowed the determination of new structures in the core oligosaccharide and the O-antigen of this lipopolysaccharide. In this work, we have reinvestigated the lipid A structure isolated from B. suis and B. abortus lipopolysaccharides. A detailed study by MALDI-TOF mass spectrometry in the positive and negative ion modes of the lipid A moieties purified from both species was performed. Interestingly, a new feature was detected: the presence of a pyrophosphorylethanolamine residue substituting the backbone. LID-MS/MS analysis of some of the detected ions allowed assurance that the Lipid A structure composed by the diGlcN3N disaccharide, mainly hexa-acylated and penta-acylated, bearing one phosphate and one pyrophosphorylethanolamine residue.

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布鲁氏菌科是革兰氏阴性细菌，会引起布鲁氏菌病，布鲁氏菌病是世界上分布最广的人畜共患病之一，通过与被感染的动物或其产品接触而传播给人类。暴露在细胞表面的脂多糖已被深入研究，被认为是布鲁氏菌的主要致病因子。近年来，结构研究允许确定核心寡糖中的新结构以及该脂多糖的O抗原。在这项工作中，我们重新研究了从猪双歧杆菌和流产双歧杆菌中分离出的脂质A结构。脂多糖。通过MALDI-TOF质谱对从这两种物种纯化的脂质A部分的正离子和负离子模式进行了详细研究。有趣的是，检测到一个新特征：取代主链的焦磷酸基乙醇胺残基的存在。对一些检测到的离子的LID-MS / MS分析可以确保由diGlcN3N二糖（主要是六酰化和五酰化）组成的脂质A结构，带有一个磷酸盐和一个焦磷酸基乙醇胺残基。

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