ISSN:
1432-1017
Keywords:
Melittin
;
membrane-bound protein conformation
;
13C-NMR
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Physics
Notes:
Abstract The orientation of melittin in lecithin membranes was investigated by means of 13C-NMR spectroscopy. Phospholipase-free melittin was labeled with 13C-methyl groups at the ω-amino side chains of lysine 7, 21, and 23. From the pH dependence of the corresponding 13C resonances, pK values of the lysine residues were derived that were different for free and membrane-bound melittin. The shift reagent Pr(NO3)3 induced shifts in the 13C resonance position of all three lysines when melittin and the shift reagent were added to a lecithin vesicle suspension, whereas Pr3+ ions included in the inner volume of the vesicles did not affect the 13C resonances of melittin bound to the outer vesicle membrane. A wedge-like structure was derived for the membrane-bound melittin, the lysine side chains of which are freely accessible to the aqueous solvent.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00255030
Permalink
