tailieunhanh - Báo cáo khoa hoc : The carbohydrate recognition domain of collectins

Collectins are effector molecules of the innate immune system that play an important role in the first line of defence against bacteria, viruses and fungi. Most of their interactions with microorganisms are mediated through their carbohydrate recognition domain (CRD), which binds in a Ca 2+ -dependent manner to glycoconjugates. Molecular | IFEBS Journal REVIEW ARTICLE The carbohydrate recognition domain of collectins Edwin J. A. Veldhuizen Martin van Eijk and Henk P. Haagsman Department of Infectious Diseases and Immunology Division of Molecular Host Defence Faculty of Veterinary Medicine Utrecht University The Netherlands Keywords C-type lectin innate immunity structure sugar-binding surfactant Correspondence H. P. Haagsman Department of Infectious Diseases and Immunology Division of Molecular Host Defence Faculty of Veterinary Medicine Utrecht University PO Box 3508TD Utrecht The Netherlands Fax 31 30 2532365 Tel 31 30 2535354 E-mail Received 13 April 2011 revised 26 May 2011 accepted 6 June 2011 doi Collectins are effector molecules of the innate immune system that play an important role in the first line of defence against bacteria viruses and fungi. Most of their interactions with microorganisms are mediated through their carbohydrate recognition domain CRD which binds in a Ca2 -dependent manner to glycoconjugates. This domain is a well-known structure that is present in a larger group of proteins comprising the C-type lectin domain family. Collectins form a subgroup within this family based on the presence of a collagen domain and the trimerization of CRDs which are essential for the ligand-binding properties of these proteins. The ligand specificity among the nine collectin members is significantly different as a result of both the structural organization of the trimers and specific sequence changes in the binding pocket of the CRD. In addition some collectin members have additional features such as N-linked glycosylation of CRD residues and additional loop structures within the CRD that have a large impact on their interaction with the glycoconjugates present on microorganisms or host cells. The availability of crystal structures of three members of the collectin family surfactant proteins A and D and mannan-binding protein provides .