Ferritin acts as a target site for the snowdrop lectin （GNA） in the midgut of the cotton leafworm Spodoptera littoralis  

作　　者：Amin Sadeghi Guy Smagghe Paul Proost Els J.M. Van Damme 

机构地区：[1]Laboratory of Agrozoology, Department of Crop Protection [2]Laboratory of Biochemistry and Glycobiology, Department of Molecular Biotechnology, Faculty of Bioscience Engineering, Ghent University, Ghent [3]Rega Institute, Laboratory of Molecular Immunology, Kathofieke Universiteit Leuven, Minderbroedersstraat 10, B-3000 Leuven, Belgium

出　　处：《Insect Science》2008年第6期513-519,共7页昆虫科学（英文版）

摘　　要：The snowdrop lectin GNA （Galanthus nivalis agglutinin） has been shown to possess insecticidal activity to a range of economically important insect pests. However, the precise mechanism of insecticidal action of GNA against insects remains unknown. In this investigation, we attempted to purify and identify receptor（s） responsible for binding of GNA in the larval midgut of a major lepidopteran pest （the cotton leafworm, Spodoptera littoralis） to better understand its mode of action. Therefore, cytoplasmic as well as membrane proteins from 800 larval midguts were chromatographed on a column with immobilized GNA. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of the proteins eluted from the GNA column followed by sequencing of the GNA-binding proteins and BLAST analyses revealed that the N-terminal sequences of a 24 kDa polypeptide purified from the cytoplasmic and membrane protein fraction revealed sequence similarity to sequences encoding heavy chain homologs of ferritin from Manduca sexta （76% sequence identity）, Calpodes ethlius （80% sequence identity） and Bombyx mori （61% sequence identity）. Furthermore, the N-terminal sequence of a 31 kDa polypeptide from the membrane protein fraction showed sequence similarity to a light chain homolog of ferritin from Manduca sexta （88% sequence identity）.The snowdrop lectin GNA （Galanthus nivalis agglutinin） has been shown to possess insecticidal activity to a range of economically important insect pests. However, the precise mechanism of insecticidal action of GNA against insects remains unknown. In this investigation, we attempted to purify and identify receptor（s） responsible for binding of GNA in the larval midgut of a major lepidopteran pest （the cotton leafworm, Spodoptera littoralis） to better understand its mode of action. Therefore, cytoplasmic as well as membrane proteins from 800 larval midguts were chromatographed on a column with immobilized GNA. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of the proteins eluted from the GNA column followed by sequencing of the GNA-binding proteins and BLAST analyses revealed that the N-terminal sequences of a 24 kDa polypeptide purified from the cytoplasmic and membrane protein fraction revealed sequence similarity to sequences encoding heavy chain homologs of ferritin from Manduca sexta （76% sequence identity）, Calpodes ethlius （80% sequence identity） and Bombyx mori （61% sequence identity）. Furthermore, the N-terminal sequence of a 31 kDa polypeptide from the membrane protein fraction showed sequence similarity to a light chain homolog of ferritin from Manduca sexta （88% sequence identity）.

关 键 词：FERRITIN Galanthus nivalis agglutinin GNA LEPIDOPTERA MIDGUT receptors Spodoptera littoralis 

分 类 号：Q963[生物学—昆虫学]