A new way of studying RNA-protein complexes, using neutron small angle scattering in solution, is described and was applied in the case of the system, yeast valyl-tRNA synthetase, interacting with its cognate and non cognate yeast tRNAs. It was shown that, when limited amounts of tRNA (either cognate or non cognate) are added to valyl-tRNA synthetase, a complex consisting of two enzyme molecules and one tRNA molecule is first formed. It is subsequently dissociated to a one to one complex when more tRNA is present in the solution. The association curve shows a maximum for a molecular ratio, enzyme over tRNA, equal to 2.

Amino Acyl-tRNA Synthetases↗

PubMed1976

Direct methods for the analysis of lamellar neutron diffraction from oriented multilayers: a difference Patterson deconvolution approach.

We have described here a direct method for the solution of the phase problem for lamellar neutron diffraction from hydrated oriented multilayers of model membranes. As a result, the neutron-scattering profiles of such model membranes can be uniquely determined. We note that such methods can easily be extended to cases in which the thickness of the water layer w is somewhat greater than d/2 as long as it is substantially less than d [e.g., w less than 3d/4 would suffice, since deltaP(-d/4 less than or equal to x less than or equal to d/4) would contain only contributions from see article without overlapping contributions from see articles and to cases in which isotopic labeling is used instead of partial H2O-D2O exchange.

Cholesterol↗

PubMed1976

Some focusing techniques and their application to low-angle neutron scattering.

Both imaging and simple converging collimator systems can provide a focused neutron beam. Each system has been tested and appears suitable for exploitation. Imaging systems employing bent multilayer monochromators can be made simply by elastically bending a flat multilayer. The periodic spacing of the multilayer can be made to match that of the sample. The converging Soller slit provides a purely geometric means of prouducing a focused beam. Wavelength spread and distribution across the beam can be controlled separately. Soller-slit technology is further advanced than that of multilayers. The experiments sketched above demonstrate that converging or focused neutron beams suitable for low-angle scattering work can be produced with existing technology. Focusing incurs little or no loss of intensity and does not seriously distort the resolution function of a low-angel instrument. It permits a small spectrometer to make use of both advanced detector technology and large samples and thus to approach the capability of a much larger machine.

Neutrons↗