caa a22 4500 475846443 CHVBK 20180406123915.0 cr unu---uuuuu 170329e20000201xx s 000 0 eng 10.1007/PL00000695 doi (NATIONALLICENCE)springer-10.1007/PL00000695 Unordered structure of proinsulin C-peptide in aqueous solution and in the presence of lipid vesicles [Elektronische Daten] [M. Henriksson*, J. Shafqat, E. Liepinsh, M. Tally, J. Wahren, H. Jörnvall, J. Johansson] Abstract.: Proinsulin C-peptide ameliorates renal and autonomic nerve function and increases skeletal muscle blood flow, oxygen uptake and glucose transport in patients with insulin-dependent diabetes mellitus. These effects have in part been ascribed to the stimulatory influence of C-peptide on Na+,K+-ATPase and endothelial nitric oxide synthase. To evaluate the capacity of C-peptide to insert into lipid bilayers and form ion channels, C-peptide secondary structure and membrane interactions were studied with circular dichroism spectroscopy and size exclusion chromatography. C-peptide is shown to lack a stable secondary structure, both when part of proinsulin and when free in aqueous solution, although the N-terminal third of the peptide exhibits an α-helical conformation in trifluoroethanol. Moreover, C-peptide remains disordered in the aqueous solvent in the presence of lipid vesicles, regardless of vesicle composition. In conclusion, C-peptide is unlikely to elicit physiological effects through stable conformation-dependent interactions with lipid membranes. Birkhäuser Verlag Basel,, 2000 Key words. Diabetes mellitus nationallicence protein secondary structure nationallicence circular dichroism nationallicence peptide-lipid interactions nationallicence insulin nationallicence Henriksson* M. Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-17177 Stockholm (Sweden), Fax +46 8 337462, e-mail: mikael.henriksson@mbb.ki.se, SE aut Shafqat J. Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-17177 Stockholm (Sweden), Fax +46 8 337462, e-mail: mikael.henriksson@mbb.ki.se, SE aut Liepinsh E. Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-17177 Stockholm (Sweden), Fax +46 8 337462, e-mail: mikael.henriksson@mbb.ki.se, SE aut Tally M. Department of Molecular Medicine, Unit for Endocrinology and Diabetes, Karolinska Institutet, Stockholm (Sweden), SE aut Wahren J. Department of Surgical Sciences, Karolinska Hospital, Stockholm (Sweden), SE aut Jörnvall H. Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-17177 Stockholm (Sweden), Fax +46 8 337462, e-mail: mikael.henriksson@mbb.ki.se, SE aut Johansson J. Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-17177 Stockholm (Sweden), Fax +46 8 337462, e-mail: mikael.henriksson@mbb.ki.se, SE aut https://doi.org/10.1007/PL00000695 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/PL00000695 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Henriksson* M. Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-17177 Stockholm (Sweden), Fax +46 8 337462, e-mail: mikael.henriksson@mbb.ki.se, SE aut NATIONALLICENCE 700 1- Shafqat J. Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-17177 Stockholm (Sweden), Fax +46 8 337462, e-mail: mikael.henriksson@mbb.ki.se, SE aut NATIONALLICENCE 700 1- Liepinsh E. Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-17177 Stockholm (Sweden), Fax +46 8 337462, e-mail: mikael.henriksson@mbb.ki.se, SE aut NATIONALLICENCE 700 1- Tally M. Department of Molecular Medicine, Unit for Endocrinology and Diabetes, Karolinska Institutet, Stockholm (Sweden), SE aut NATIONALLICENCE 700 1- Wahren J. Department of Surgical Sciences, Karolinska Hospital, Stockholm (Sweden), SE aut NATIONALLICENCE 700 1- Jörnvall H. Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-17177 Stockholm (Sweden), Fax +46 8 337462, e-mail: mikael.henriksson@mbb.ki.se, SE aut NATIONALLICENCE 700 1- Johansson J. Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-17177 Stockholm (Sweden), Fax +46 8 337462, e-mail: mikael.henriksson@mbb.ki.se, SE aut Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer