![]()
|
|
||||||||
J. Biol. Chem., Vol. 266, Issue 15, 9403-9407, May, 1991
E Jhun, BH Jhun, LR Jones and CY Jung
Biophysics Laboratory, Veterans Administration Medical Center, Buffalo, New York 14215.
The 12 transmembrane alpha helices (TMHs) of human erythrocyte glucose transporter were individually cut by pepsin digestion as membrane-bound 2.5-3.5-kDa peptide fragments. Radiation-induced chemical degradation of these fragments showed an average target size of 34 kDa. This is 10- 12 x larger than the average size of an individual TMH, demonstrating that a significant energy transfer occurs among these TMHs in the absence of covalent linkage. Heating this TMH preparation at 100 degrees C for 15 min reduced the target size to 5 kDa or less, suggesting that the noncovalent energy transfer requires specific helix- helix interactions. Purified phospholamban, a small (6-kDa) integral membrane protein containing a single TMH, formed a pentameric assembly in sodium dodecyl sulfate. The chemical degradation target size of this phospholamban pentamer was 5-6 kDa, illustrating that not all integral membrane protein assemblies permit intersubunit energy transfer. These findings together with other published observations suggest strongly that significant noncovalent energy transfer can occur within the tertiary and quaternary structure of membrane proteins and that as yet undefined proper molecular interactions are required for such covalent energy transfer. Our results with pepsin-digested glucose transporter also illustrate the importance of the interhelical interaction as a predominating force in maintaining the tertiary structure of a transmembrane protein.
This article has been cited by other articles:
![]() |
B.S.S. Rao, R. Shanbhoge, D. Upadhya, G.C. Jagetia, S.K. Adiga, P. Kumar, K. Guruprasad, and P. Gayathri Antioxidant, anticlastogenic and radioprotective effect of Coleus aromaticus on Chinese hamster fibroblast cells (V79) exposed to gamma radiation Mutagenesis, July 1, 2006; 21(4): 237 - 242. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Karbownik and R. J. Reiter Antioxidative Effects of Melatonin in Protection Against Cellular Damage Caused by Ionizing Radiation Experimental Biology and Medicine, October 1, 2000; 225(1): 9 - 22. [Abstract] [Full Text] |
||||
![]() |
M. Lachaal, A. L. Rampal, W. Lee, Y.-w. Shi, and C. Y. Jung GLUT1 Transmembrane Glucose Pathway J. Biol. Chem., March 1, 1996; 271(9): 5225 - 5230. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| All ASBMB Journals | Molecular and Cellular Proteomics |
| Journal of Lipid Research | ASBMB Today |