![]()
|
|
||||||||
JBC, Vol. 250, Issue 11, 4268-4277, Jun, 1975
J. C. Sodoyez, F. Sodoyez-Goffaux, M. M. Goff, A. E. Zimmerman and E. R. Arquilla
Insulin was enzymatically moniodinated with 127-I or 125-I, and an improved
method of purification by anion exchange chromatography was employed.
(127-I)Monoiodoinsulin was identified by spectrophotometric analysis and
its molar extinction coefficient determined to be 6.31 times 10-3 M-1 cm
minus 1. The observed specific activity of carrier-free
(125-I)monoidoinsulin was close to the theoretical value (378mCi/mg). The
monoiodotyrosyl residue of monoidoinsulin was shown to be solvent-exposed.
The ionic properties of the substituted hormone were altered at pH values
close to the pK of monoiodotyrosine (8.85), but the pI was unchanged
(5.65). (127-I)Monoiodoinsulin formed rhombohedral crystals and
co-crystallized with native insulin. Monoidoinsulin was indistinguishable
from insulin with respect to binding to two out of three guinea pig
anti-insulin sera, to binding to IM9 cultured human lymphocytes, and to
binding to isolated rat hepatocyte plasma membranes. The potency of
monoidoinsulin was not statistically different from that of insulin in the
rat fat cell bioassay and in the mouse convulsion assay. An
insulin-degrading enzyme extracted from rat liver degraded monoiodoinsulin
less readily than native insulin; monoiodoinsulin was a competitive
inhibitor of insulin degradation, and the Km values were 30 nM AND 78 NM
for monoidoinsulin and native insulin, respectively. It is concluded that
monoidination does not markedly alter the three-dimensional structure of
the molecule and that only a few sensitive biological systems are able to
distinguish the monoidinated from the native hormone.
[127-I]- or carrier-free [125-I]monoiodoinsulin
![]()
CiteULike
Complore
Connotea
Del.icio.us
Digg
Reddit
Technorati What's this?
This article has been cited by other articles:
![]() |
R. P. Radcliff, B. L. McCormack, D. H. Keisler, B. A. Crooker, and M. C. Lucy Partial Feed Restriction Decreases Growth Hormone Receptor 1A mRNA Expression in Postpartum Dairy Cows J Dairy Sci, February 1, 2006; 89(2): 611 - 619. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Sodoyez, F Sodoyez-Goffaux, M Guillaume, and G Merchie [123I]Insulin metabolism in normal rats and humans: external detection by a scintillation camera Science, February 18, 1983; 219(4586): 865 - 867. [Abstract] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| All ASBMB Journals | Molecular and Cellular Proteomics |
| Journal of Lipid Research | ASBMB Today |