Substance P, Free Acid


The conformation of substance P (free acid) (SPOH) has been investigated in dimethylsulfoxide (DMSO), water and dipalmitoylphosphotidylcholine (DPPC) bilayers by two-dimensional NMR and restraint molecular dynamics simulations. The observed NOE patterns for substance P (free acid) in these media are very much different from each other. The conformation of substance P (free acid) in DPPC bilayers is characterized by gamma-bends at Pro4,Gln6and Phe7, which are stabilized by hydrogen bonding between Lys3CO–>Gln5NH, Gln5CO–>Phe7NH and Gln6CO–>Phe8NH, respectively. The absence of biological activity in SPOH has been attributed to the absence of any helix like structure at the central residues and absence of any interresidue interaction with C-terminal OH group, in DPPC bilayers, a feature shown to be an important prerequisite for SP and SP agonists to bind to the NKI tachykinin receptor.

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% Peak Area By HPLC ≥ 95%


TFA Salt



Store at -20°C. Store under desiccating conditions. The product can be stored for up to 12 months.



This product as supplied is intended for research use only, not for use in human, therapeutic or diagnostic applications without the expressed written authorization of United States Biological.





5 mg, 10 mg, Other