Preparation and properties of (monoiodotyrosine)-insulin

B1-3,5-diiodotyrosine insulin: A valid tracer for insulin

“…In an attempt to overcome this problem Freychet et al [25] purified monoiodoinsulin from a crude iodination mixture and demonstrated full activity of the product in vitro. However others have found purified monoiodoinsulins to be only partially active [26][27][28] or completely inactive [29]. The biological activities of some of these monoiodoinsulin preparations [26,27,29] correlated directly with the percentage of their radioactivit~r in the A14 position, consistent with the observation by Garratt et al [30] that iodination of A19 resulted in a reduced activity of the hormone.…”

“…However others have found purified monoiodoinsulins to be only partially active [26][27][28] or completely inactive [29]. The biological activities of some of these monoiodoinsulin preparations [26,27,29] correlated directly with the percentage of their radioactivit~r in the A14 position, consistent with the observation by Garratt et al [30] that iodination of A19 resulted in a reduced activity of the hormone. However the preparation of Linde and Hansen [28] showed the reverse trend.…”

Improved Preparation of Semisynthetic PheB1-Tritiated Insulin

“…Since chemical determination of insulin in high specific activity preparations at low insulin concentrations is difficult, the quantification of insulin for the purposes of calculating the specific activities attained in the various [ 3 H]insulin preparations used in this investigation, was done by standard radio immuno- Table 1. Distribution of radioactivity in a commercial L- [2,3,4,5, Hlphenylalanine preparation. The L- [2,3,4,5, HJphenylalanine was run with 1 Mg carrier on a Cellulose MN-30 TLC plate developed with n-butanol/acetic acid/ water (12:3:5) and quantitatively analysed by scraping the stationary phase off the plate and counting in liquid scintillation fluid.…”

“…Distribution of radioactivity in a commercial L- [2,3,4,5, Hlphenylalanine preparation. The L- [2,3,4,5, HJphenylalanine was run with 1 Mg carrier on a Cellulose MN-30 TLC plate developed with n-butanol/acetic acid/ water (12:3:5) and quantitatively analysed by scraping the stationary phase off the plate and counting in liquid scintillation fluid. The insulin had been separated from the coupling mixture by exclusion chromatography (see Fig.…”