کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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2803685 | 1156748 | 2006 | 11 صفحه PDF | دانلود رایگان |

Insulin and insulin-like growth factor receptors (IR, IGF-IR, IGF-IIR) from human placental cell membranes were solubilised and their glycoprotein properties were studied in terms of their interaction with five lectins: wheat germ agglutinin (WGA), banana lectin (BanLec), phytohaemagglutinin (PHA), concanavalin A (Con A), and Sambucus nigra agglutinin (SNA). The pattern of binding to the immobilised lectins indicated that the glycosylation of the IGF-IR, IGF-IIR and IR differed. We found several populations of receptors in placental cell membranes, differing with respect to their oligosaccharide moieties. IGF-IIR populations bore highly branched complex type N-glycans with a very high content of oligosaccharides terminating with Sia, high-mannose type N-glycans and hybrid type N-glycans. All these glycans seemed to be attached to the same IGF-II receptor molecules. Two major glycoforms of IR were detected, one having multiple highly branched N-glycans with a low content of terminal Sia and the other, having high-mannose type glycans attached to multiple N-glycosylation sites. As for the IGF-IR, multiple glycoforms were detected, bearing complex type N-glycans with various content of Sia-terminating branches, hybrid type N-glycans or high-mannose type N-glycans. The specific binding of 125I-IGF-II to its receptor increased in the presence of immobilised WGA and SNA, which might imply the existence of a mammalian lectin counterpart whose potential physiological significance may lie in different targeting to various membrane compartments, thereby potentially modifying their cell signalling pathways.
Journal: Growth Hormone & IGF Research - Volume 16, Issue 3, June 2006, Pages 174–184