The 500 MHz proton spectra of monomeric bacteriochlorophyll a and chlorophyll a were recorded and assigned. The proton chemical shifts and proton-proton coupling constants were all determined except for the P-5 to P-15 phytyl side-chain protons. The conformational structures of the reduced rings an
High-field magnetic birefringence study of the structure of rodlike phages Pf1 and fd in solution
✍ Scribed by J. Torbet; G. Maret
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 1981
- Tongue
- English
- Weight
- 712 KB
- Volume
- 20
- Category
- Article
- ISSN
- 0006-3525
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
The magnetic orientation of the rodlike bacterial viruses Pf1 and fd in dilute aqueous solution was detected by high‐resolution birefringence measurements. Partial alignment takes place parallel to the magnetic field chiefly due to the diagmagnetic anisotropy of the highly ordered α‐helices in the coat protein. It follows from the analysis of the experimental diamagnetic anisotropy that in both phages the α‐helices and aromatic amino acids are oriented relatively parallel to the phage axis. In Pf1 these become, on average, more nearly parallel as the temperature is reduced from about 25 to 5°C. These results demonstrate that high‐resolution magnetically induced birefringence measurements can be used to investigate some general structural features of complicated biological particles in solution.
📜 SIMILAR VOLUMES
A chiral bradicardisant benzazepine-type drug with an asymmetric carbon and a tertiary amino nitrogen was studied as the chloride salt. X-ray analysis in the solid state of the salt formed upon protonation of the base shows the occurrence in the unit cell of two diastereomeric species with horseshoe
H , =C, ' \* N and 19%g N M R data were obtained for organomercury fuIminates, RHgCNO (R=Me, Ph, CNO). The relatively slow relaxation processes effective for the quadrupolar nitrogen muclei of these compounds allow the detection of -g-l4N scalar coupling constants. This feature is ascribed to the pr