PubMed:10319440 JSONTXT

{"project":"silkworm","denotations":[{"id":"T1","span":{"begin":27,"end":30},"obj":"Gene:100146105"},{"id":"T2","span":{"begin":43,"end":69},"obj":"Chemical:-"},{"id":"T3","span":{"begin":127,"end":138},"obj":"Species:7091"},{"id":"T4","span":{"begin":169,"end":172},"obj":"Gene:100146105"},{"id":"T5","span":{"begin":295,"end":303},"obj":"Species:7091"},{"id":"T6","span":{"begin":305,"end":316},"obj":"Species:7091"},{"id":"T7","span":{"begin":427,"end":430},"obj":"Gene:100146105"},{"id":"T8","span":{"begin":546,"end":549},"obj":"Gene:100146105"},{"id":"T9","span":{"begin":600,"end":609},"obj":"Chemical:MESH:D004220"},{"id":"T10","span":{"begin":622,"end":625},"obj":"Gene:100146105"},{"id":"T11","span":{"begin":694,"end":697},"obj":"Gene:100146105"},{"id":"T12","span":{"begin":777,"end":780},"obj":"Gene:100146105"},{"id":"T13","span":{"begin":810,"end":836},"obj":"Chemical:-"},{"id":"T14","span":{"begin":973,"end":976},"obj":"Gene:100146105"},{"id":"T15","span":{"begin":1049,"end":1064},"obj":"Chemical:MESH:D009844"},{"id":"T16","span":{"begin":1187,"end":1190},"obj":"Gene:100146105"},{"id":"T17","span":{"begin":1338,"end":1341},"obj":"Chemical:MESH:D001216"},{"id":"T18","span":{"begin":1366,"end":1369},"obj":"Gene:100146105"}],"text":"Hydrophobic interaction of P25, containing Asn-linked oligosaccharide chains, with the H-L complex of silk fibroin produced by Bombyx mori.\nFibroin light (L-) chain and P25 are low molecular weight protein components of silk fibroin which are secreted from the posterior silk gland cells of the silkworm, Bombyx mori. The primary structure of L-chain was determined previously by cDNA cloning and peptide analysis, but that of P25 has only been deduced from its genomic sequence. Our previous studies with specific antibodies against L-chain and P25 have shown that L-chain and H-chain are linked by disulfide bond(s) but P25 is not covalently linked to H-chain. Here, we present evidence that P25 associates with the H-L complex primarily by hydrophobic interactions and that P25 is a glycoprotein containing Asn-linked oligosaccharide chains. From the analysis of three fibroin-secretion-deficient 'naked pupa' mutant breeds [Nd(2), Nd-s and Nd-sD], it is suggested that P25 interacts with H-chain in the absence of H-L linkage but its content of oligosaccharide is reduced when the H-L linkage is not formed. From these results, models are presented implying that the H-L complex and P25 are associated to form a higher-order complex of specific conformation during the processes of intracellular transport and secretion, and that the Asn-linked glycosylation of P25 is partially altered under such conditions."}