Details

Autor(en) / Beteiligte

• Twigg, Stephen M
• Kiefer, Michael C
• Zapf, Jürgen
• Baxter, Robert C

Titel

A Central Domain Binding Site in Insulin-Like Growth Factor Binding Protein-5 for the Acid-Labile Subunit

Ist Teil von

• Endocrinology (Philadelphia), 2000-01, Vol.141 (1), p.454-457

Ort / Verlag

United States: Endocrine Society

Erscheinungsjahr

2000

Link zum Volltext

Quelle

Oxford Journals 2020 Medicine

Beschreibungen/Notizen

• Like insulin-like growth factor binding protein-3 (IGFBP-3), IGFBP-5 forms a ternary complex with insulin-like growth factor (IGF)-I or IGF-II, and the acid-labile subunit (ALS). The study of IGFBP-5/IGFBP-6 chimeric proteins with amino-terminal and middle domain swaps, has revealed the existence of a site in the middle domain of IGFBP-5, that binds to ALS in the absence of the IGFBP-5 carboxy-terminal domain. An IGFBP-6 chimeric protein containing the central domain of IGFBP-5 complexed efficiently with ALS, and a carboxy-terminally truncated IGFBP-5 mutant, IGFBP-51-169, also bound to ALS in the presence of IGFs, although with much less potency than full length rhIGFBP-5. In contrast to the latter, IGFBP-51-169 preferentially formed ternary complexes with IGF-II rather than IGF-I. These results indicate that a site which binds ALS exists in IGFBP-5 mutants which lack the IGFBP-5 carboxy-terminal domain.