TY - JOUR
T1 - Small angle X-ray scattering-based elucidation of the self-association mechanism of human insulin analogue lys(B29)(N(e)¿-carboxyheptadecanoyl) des(B30)
AU - Jensen, Malene Hillerup
AU - Wahlund, Per-Olof
AU - Toft, Katrine Nørgaard
AU - Jacobsen, Jes Kristian
AU - Steensgaard, Dorte Bjerre
AU - van de Weert, Marco
AU - Havelund, Svend
AU - Vestergaard, Bente
PY - 2013/1/15
Y1 - 2013/1/15
N2 - Lys(B29)(N(e)¿-carboxyheptadecanoyl) des(B30) human insulin is an insulin analogue belonging to a class of analogues designed to form soluble depots in subcutis by self-association, aiming at a protracted action. On the basis of small angle X-ray scattering (SAXS) supplemented by a range of biophysical and structural methods (field flow fractionation, dynamic and multiangle light scattering, circular dichroism, size exclusion chromatography, and crystallography), we propose a mechanism for the self-association expected to occur upon subcutaneous injection of this insulin analogue. SAXS data provide evidence of the in solution structure of the self-associated oligomer, which is a long straight rod composed of "tense" state insulin hexamers (T(6)-hexamers) as the smallest repeating unit. The smallest oligomer building block in the process is a T(6)T(6)-dihexamer. This tense dihexamer is formed by the allosteric change of the initial equilibrium between a proposed "relaxed" state R(6)-hexamer and an R(3)T(3)T(3)R(3)-dihexamer. The allosteric change from relaxed to tense is triggered by removal of phenol, mimicking subcutaneous injection. The data hence provide the first unequivocal evidence of the mechanism of self-association for this type of insulin analogue.
AB - Lys(B29)(N(e)¿-carboxyheptadecanoyl) des(B30) human insulin is an insulin analogue belonging to a class of analogues designed to form soluble depots in subcutis by self-association, aiming at a protracted action. On the basis of small angle X-ray scattering (SAXS) supplemented by a range of biophysical and structural methods (field flow fractionation, dynamic and multiangle light scattering, circular dichroism, size exclusion chromatography, and crystallography), we propose a mechanism for the self-association expected to occur upon subcutaneous injection of this insulin analogue. SAXS data provide evidence of the in solution structure of the self-associated oligomer, which is a long straight rod composed of "tense" state insulin hexamers (T(6)-hexamers) as the smallest repeating unit. The smallest oligomer building block in the process is a T(6)T(6)-dihexamer. This tense dihexamer is formed by the allosteric change of the initial equilibrium between a proposed "relaxed" state R(6)-hexamer and an R(3)T(3)T(3)R(3)-dihexamer. The allosteric change from relaxed to tense is triggered by removal of phenol, mimicking subcutaneous injection. The data hence provide the first unequivocal evidence of the mechanism of self-association for this type of insulin analogue.
U2 - 10.1021/bi3008615
DO - 10.1021/bi3008615
M3 - Journal article
C2 - 23256662
VL - 52
SP - 282
EP - 294
JO - Biochemistry
JF - Biochemistry
SN - 0006-2960
IS - 2
ER -