B9-serine residue is crucial for insulin actions in glucose metabolism.
OBJECTIVE
To explore the importance of B9 and B10 amino acid residues in the insulin molecule.


METHODS
The [B9Glu, B10Asp] insulin (E,D-insulin) receptor binding activity, glucose upta ke activity, and lipogenesis activity were measured in isolated adipocytes. The translocation of glucose transporter 4 (Glut4) and the phosphorylation of insulin receptor (IR) stimulated by E, D-insulin were determined by Western blotting.


RESULTS
Compared with native insulin, the receptor binding activity of E,D-insulin was 31 %; the stimulating activity of E,D-insulin in glucose transport and lipogenesis were 45 % and 40 % respectively; the stimulations of Glut4 translocation and insulin receptor autophosphorylation of E,D-insulin were about 58 % and 46 % respectively.


CONCLUSIONS
B9-serine residue is crucial for insulin actions in glucose metabolism.
Liao
Z Y
ZY
Institute of Biochemistry, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China.
Tang
Y H
YH
Xu
M H
MH
Feng
Y M
YM
Zhu
S Q
SQ
D017667:Adipocytes / Q000378:metabolism; D000818:Animals; D001665:Binding Sites; D002469:Cell Separation; D004822:Epididymis / Q000378:metabolism; D005947:Glucose / Q000378:metabolism*; D007328:Insulin / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D008297:Male; D009004:Monosaccharide Transport Proteins / Q000378:metabolism; D010766:Phosphorylation; D051381:Rats; D017207:Rats, Sprague-Dawley; D011972:Receptor, Insulin / Q000378:metabolism*; D012694:Serine / Q000378:metabolism / Q000494:pharmacology*; D014178:Translocation, Genetic
D007328:Insulin; D009004:Monosaccharide Transport Proteins; C058172:insulin, Asp(B9)-Glu(B27)-; D012694:Serine; D011972:Receptor, Insulin; D005947:Glucose