The Giardia intestinalis filamentous cyst wall contains a novel β(1-3)-N-acetyl-D-galactosamine polymer: a structural and conformational study

Assembly of a protective cyst wall by Giardia is essential for the survival of the parasite outside the host intestine and for transmission among susceptible hosts. The structure of the G. intestinalis filamentous cyst wall was studied by chemical methods, mass spectrometry, and 1H nuclear magnetic resonance spectroscopy. Isolated cyst wall material contains carbohydrate and protein in a ratio of 3:2 (w/w), and the carbohydrate moiety is composed of a