Human [Leu24] [Ala31] IGF-I

Human [Leu24][Ala31]insulin-like Growth Factor-I ([Leu24][Ala31]IGF-I) is an analogue of human IGF-I which has an Leucine substitution in place of Tyrosine at position 24 and an Alanine substitution in place of Tyrosine at position 31 of the human IGF-I sequence. [Leu24][Ala31]IGF-I has greatly reduced binding to the type 1 IGF receptor and to the insulin receptor compared to IGF-I, [Leu24] IGF-I and [Leu60] IGF-I. However [Leu24] [Ala31] IGF-I has normal binding to acid-stripped human serum binding proteins. Consequently [Leu24] [Ala31] IGF-I is an extremely useful analogue of IGF-I for investigating IGF actions independent of binding to the type 1 IGF receptor.