Biomedical subjects

Lin Jiang

Publications and source records attributed to Lin Jiang.

25 records · Page 2Linked to original sources

PubMed2004

[Study on tissue culture of Ficus hirta].

The tissue culture of Ficus hirta Vahl. was studied. The nodes were used as explants and 1/2MS media with different plant growth regulators were tested. The result showed that the adventitious bud differentiation medium was 1/2MS + BA1.0 mg/L + NAA1.0 mg/L and 1/2MS + BA1.5 mg/L + NAA0.5 mg/L, the media for multiplication was 1/2MS +6 - BA0.5 mg/L, and the medium for rooting was 1/2MS + IBA1 mg/L. The cause of nigrescence in the tissue culture and its preventive methods were also discussed in this paper.

Ascorbic Acid↗

PubMed2003

Beyond the rotamer library: genetic algorithm combined with the disturbing mutation process for upbuilding protein side-chains.

The disturbing genetic algorithm, incorporating the disturbing mutation process into the genetic algorithm flow, has been developed to extend the searching space of side-chain conformations and to improve the quality of the rotamer library. Moreover, the growing generation amount idea, simulating the real situation of the natural evolution, is introduced to improve the searching speed. In the calculations using the pseudo energy scoring function of the root mean squared deviation, the disturbing genetic algorithm method has been shown to be highly efficient. With the real energy function based on AMBER force field, the program has been applied to rebuilding side-chain conformations of 25 high-quality crystallographic structures of single-protein and protein-protein complexes. The averaged root mean standard deviation of atom coordinates in side-chains and veracities of the torsion angles of chi(1) and chi(1) + chi(2) are 1.165 A, 88.2 and 72.9% for the buried residues, respectively, and 1.493 A, 79.2 and 64.7% for all residues, showing that the method has equal precision to the program SCWRL, whereas it performs better in the prediction of buried residues and protein-protein interfaces. This method has been successfully used in redesigning the interface of the Basnase-Barstar complex, indicating that it will have extensive application in protein design, protein sequence and structure relationship studies, and research on protein-protein interaction.

Algorithms↗

PubMed2003

[Effects of additives on tissue culture and rapid propagation of Dendrobium canducum].

Effects of additives on tissue culture and rapid propagation of Dendrobium canducum Walla. ex Lindal. by 1/2 MS added activated charcoal, plant growth regulators, banana juice, apple juice and potato juice were studied. The result showed that the medium 1/2 MS + 0.1 mg/L NAA + 0.5% activated charcoal was suitable for propagation of protocorm-like body (PLB), the medium 1/2 MS + 0.5 mg/L 6-BA + 0.5% activated charcoal was suitable for differentiation of PLB, and 0.5% activated charcoal, banana juice and apple juice could promote root formation and growth.

Charcoal↗

PubMed2003

[Cloning and expression of Yersinia pestis V antigen in Escherichia coli BL21 (DE3)].

The structure gene of V antigen was amplified from the wild strain of Yersinia pestis by means of PCR, and was cloned into vector pET-42b (+). Then, V antigen was successfully expressed in E. coli BL21(DE3) with the induction of IPTG. The expressing amount of the aim protein is as high as 32.8 percent of the total bacterial protein.

Antigens, Bacterial↗

PubMed2002

CH...O hydrogen bonds at protein-protein interfaces.

For the first time, a statistical potential has been developed to quantitatively describe the CH.O hydrogen bonding interaction at the protein-protein interface. The calculated energies of the CH.O pair interaction show a favorable valley at approximately 3.3 A, exhibiting a feature typical of an H-bond and similar to the ab initio quantum calculation result (Scheiner, S., Kar, T., and Gu, Y. (2001) J. Biol. Chem. 276, 9832-9837). The potentials have been applied to a set of 469 protein-protein complexes to calculate the contribution of different types of interactions to each protein complex: the average energy contribution of a conventional H-bond is approximately 30%; that of a CH.O H-bond is 17%; and that of a hydrophobic interaction is 50%. In some protein-protein complexes, the contribution of the CH.O H-bond can reach as high as approximately 40-50%, indicating the importance of the CH.O H-bond at the protein interface. At the interfaces of these complexes, C(alpha)H.O H-bonds frequently occur between adjacent strands in both parallel and antiparallel orientations, having the obvious structural motif of bifurcated H-bonds. Our study suggests that the weak CH.O H-bond makes an important contribution to the association and stability of protein complexes and needs more attention in protein-protein interaction studies.

Amino Acid Sequence↗

PubMed2002

Potential of mean force for protein-protein interaction studies.

Calculating protein-protein interaction energies is crucial for understanding protein-protein associations. On the basis of the methodology of mean-field potential, we have developed an empirical approach to estimate binding free energy for protein-protein interactions. This knowledge-based approach has been used to derive distance-dependent free energies of protein complexes from a nonredundant training set in the Protein Data Bank (PDB), with a careful treatment of homology. We calculate atom pair potentials for 16 pair interactions, which can reflect the importance of hydrophobic interactions and specific hydrogen-bonding interactions. The derived potentials for hydrogen-bonding interactions show a valley of favorable interactions at a distance of approximately 3 A, corresponding to that of an established hydrogen bond. For the test set of 28 protein complexes, the calculated energies have a correlation coefficient of 0.75 compared with experimental binding free energies. The performance of the method in ranking the binding energies of different protein-protein complexes shows that the energy estimation can be applied to value binding free energies for protein-protein associations.

Databases, Protein↗

PubMed2002

[Preliminary evidence that a hepatitis E virus (HEV) ORF2 recombinant protein protects cynomolgus macaques against challenge with wild-type HEV].

BACKGROUND: To observe the protective effect of hepatitis E virus (HEV) ORF2 recombinant protein expressed in prokaryote cell cynomolgus macaques (cynos) against challenging with wild-type HEV. METHODS: Cynos were immunized with HEV ORF2 recombinant protein and then challenged with wild-type HEV, the unimmunized cynos were used as control. Blood samples were collected and tested to see if there were dynamic changes of ALT and antibody to HEV before and after challenge with wild-type HEV. RESULTS: All the five unimmunized cynos re-presented hepatitis 3 weeks after challenging with wild-type HEV. However, all the five immunized cynos showed no hepatitis and pathological changes. CONCLUSIONS: Cynos can be efficiently protected by immunization with HEV ORF2 recombinant protein against wild-type HEV. This protein can be a promising candidate for HEV vaccine.

Animals↗