Preferential conformation of substance P in solution.
The three-dimensional structure of substance P has been studied by 1H-NMR, (500 MHz), and by circular dichroism (CD) in different solvents. The analysis of the different NMR parameters suggest that substance P adopts a rather extended structure in dimethylsulfoxide and pyridine. In water, besides the aggregation phenomenon, the monomeric substance P presents a complex conformational equilibrium. The addition of sodium dodecylsulfate to the aqueous solution induces, as shown by CD spectroscopy, a preferential alpha-helical conformation. And in methanol three structural conclusions may be drawn: the flexibility of the N-terminal Arg-Pro-Lys, the alpha-helical structure of Pro4-Gln5-Gln6-Phe7-Phe8 and the interaction of the C-terminal carboxamide with the primary amides from both glutamines.
G
G
Chassaing
O
O
Convert
S
S
Lavielle
D002942:Circular Dichroism; D004121:Dimethyl Sulfoxide; D009682:Magnetic Resonance Spectroscopy; D000432:Methanol; D008958:Models, Molecular; D011487:Protein Conformation; D011725:Pyridines; D012996:Solutions; D013373:Substance P; D014867:Water
D011725:Pyridines; D012996:Solutions; D014867:Water; D013373:Substance P; C023666:pyridine; D000432:Methanol; D004121:Dimethyl Sulfoxide