Open AccessMolecular Cloning of Two Different Mannose‐Binding Lectins from Tulip Bulbs
Author(s) -
Damme Els J. M.,
Briké Filip,
Winter Harry C.,
Leuven Fred,
Goldstein Irwin J.,
Peumans Willy J.
Publication year - 1996
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1996.00419.x
Subject(s) - mannan binding lectin , lectin , mannose , biology , ficolin , c type lectin , molecular cloning , biochemistry , cd69 , binding site , peptide sequence , expression cloning , complementary dna , gene , cytotoxic t cell , il 2 receptor , in vitro
Two lectins were isolated from the bulbs of Tulipa cv. Apeldoom and their corresponding cDNA clones analyzed. The first, called TxLMII (second mannose‐binding Tulipa hybrid lectin), is a novel mannose‐binding tulip lectin. Based on its molecular structure, carbohydrate‐binding specificity and amino acid sequence, TxLMII belongs to the superfamily of mannose‐binding monocot lectins which are also found in representatives of the plant families Amaryllidaceae, Alliaceae, Orchidaceae and Araceae. Molecular cloning of the second lectin, called TxLCI (first Tulipa hybrid lectin with complex specificity), allowed determination unambiguously of the molecular structure of this previously described protein. In addition, evidence is presented that each TxLCI subunit possesses a mannose‐binding site and an N ‐acetylgalactosamine‐binding site, which act independently of each other. Both binding sites are located in a separate domain of the lectin polypeptide. Since the first domain of TxLCT shows sequence similarity to TxLMII, it is suggested that their genes evolved from a common ancestor.