Abstract: | The 270 MHz n.m.r. spectra of phosphoserine (PSer) have been measured and completely analysed for seven pD values. The resulting vicinal coupling constants 3J(HαHβ) and 3J(PHβ) are used to discuss the conformations of PSer with respect to the (Hα)? Cα? Cβ? (O) and (Cα)? Cβ? O? (P) bond axes. The all-trans conformer predominates for all pD values, with its fractional population being minimal at pD values close to neutrality. The Cβ? O bond rotamer populations agree reasonably well with those obtained from 13C investigations. |