Three-dimensional structure of the HSV1 nucleocapsid

The three-dimensional structures of full and empty capsids of HSV1 were determined by computer analysis of low dose cryo-electron images of ice embedded capsids. The full capsid structure is organized into outer, intermediate, and inner structural layers. The empty capsid structure has only one layer which is indistinguishable from the outer layer of the full capsids. This layer is arranged according to T = 16 icosahedral symmetry. The intermediate layer of full capsids appears to lie on a T = 4 icosahedral lattice. The genomic DNA is located inside the T = 4 shell and is the component of the innermost layer of the full capsids. The outer and intermediate layers interact in such a way that the channels along their icosahedral two-fold axis coincide and form a direct pathway between the DNA and the environment outside the capsid.     

Changing frequency of interim analysis in sequential monitoring

In clinical trial data monitoring, one can either introduce a discrete sequential boundary for a set of specified decision times or adopt a use function and then derive the boundary when data are monitored. If the use function approach is employed, one can adjust the frequency of data monitoring as long as the decision is not data-dependent. However, if the frequency of future data monitoring is affected by the observed data, then the probability of Type I error will no longer be preserved exactly. But the effect on the significance level and power is very small, perhaps negligible, as indicated by simulation results.     

Water and polypeptide conformations in the gramicidin channel. A molecular dynamics study.

Theoretical studies of ion channels address several important questions. The mechanism of ion transport, the role of water structure, the fluctuations of the protein channel itself, and the influence of structural changes are accessible from these studies. In this paper, we have carried out a 70-ps molecular dynamics simulation on a model structure of gramicidin A with channel waters. The backbone of the protein has been analyzed with respect to the orientation of the carbonyl and the amide groups. The results are in conformity with the experimental NMR data. The structure of water and the hydrogen bonding network are also investigated. It is found that the water molecules inside the channel act as a collective chain; whereas the conformation in which all the waters are oriented with the dipoles pointing along the axis of the channel is a preferred one, others are also accessed during the dynamics simulation. A collective coordinate involving the channel waters and some of the hydrogen bonding peptide partners is required to describe the transition of waters from one configuration to the other.     

Human metallothionein genes: structure of the functional locus at 16q13

The functional human metallothionein (MT) genes are located on chromosome 16q13. We have physically mapped the functional human MT locus by isolation and restriction digest mapping of cloned DNA. The mapped region contains all sequences on chromosome 16 that hybridize to metallothionein gene probes and comprises 14 tightly linked MT genes, 6 of which have not been previously described. This analysis defines the genetic limits of metallothionein functional diversity in the human genome.     

白腹锦鸡机体营养成分的分析与探讨

本文报道笼养和野生白腹锦鸡机体营养成分及其差异。分析表明,笼养的比野生种营养成分含量高的有:腿肌蛋白质高11％,胸肌、腿肌、全血的氨基酸分别高2.64％,1.39％和4.68％,胸肌、腿肌和肝脏的碳水化合物分别高0.076％、0.092％和3.962％,胸肌和腿肌的维生素A分别高188.63和84.09 I.U.,胸肌和腿肌的维生素D分别高47.2和12.8 I.U.。但是胸肌蛋白质含量笼养的比野生的低26％。     

Identification and characterization of a pregnane steroid recognition site that is functionally coupled to an expressed GABAA receptor

Conclusion Based on the pharmacological and biochemical evidence to date, especially that derived from the recombinantly expressed receptor studies, the suggestion that a novel GBRC-linked steroid recognition site exists becomes a cogent argument. The high affinity of the steroid site for certain naturally occurring metabolites of progesterone and glucocorticoids favors a physiologic role for these steroids in the regulation of brain excitability. Clearly, investigations of such a regulatory role is warranted. If present, it provides an important example of endocrine control of a major inhibitory neurotransmitter in the CNS. Moreover, as we gain a greater understanding of the molecular organization of the GBRC, the putative steroid site provides a novel target for the rational design of therapeutic agents for the treatment of anxiety, epilepsy, and insomnia.Special issue dedicated to Dr. Eugene Roberts.