PG1 Culture of Haemophilus paragallinarum

Chang Lin-Huang, Yu Wan-Chin

Institute of Organic and Polymeric Materials of the National Taipei University of Technology

 

Infectious coryza, an economically important disease for the poultry industry, is an acute respiratory disease of chickens caused by Haemophilus paragallinarum (HP). This infectious disease occurs worldwide and produces significant economic losses due to an increased number of culls and a marked drop in egg production, affecting particularly multi-age farms. Commercial vaccines for infectious coryza, typically based on killed HP, are widely available around the world. To reduce the cost of vaccine production, we studied the culture conditions for an H. paragallinarum strain isolated in Taiwan.

 

 

PG2 Site specificity of \-H abstraction reaction among secondary structure motif V An ab-intio Study

Hsiu-Feng Lua*, Feng-Yin Lib* and S. H. Lina

aThe Institute of Atomic and Molecular Sciences, Academia Sinica, P. O. Box 23-166, Taipei, Taiwan 106, R.O.C.
bDepartment of Chemistry, National Chung Hsing University, Taichung, Taiwan 402, R.O.C

 

The initial step of protein oxidation is studied through \-H abstraction by an OH radical with various secondary structure motifs of proteins and found that there exist preferential \-Hs in this kind of abstractions. The typical abstraction mechanism involves three steps, forming a pre-reactive complex before abstraction, the abstraction reaction and the H2O detachment from a post-reactive complex to form the product, C\-center radical. Using the stability of the pre-reactive complex and the reaction barrier, we provide some explanation for this site preference. The feasibility of \-H abstraction by OH radical depends not only on the types of secondary structure, but also on the reaction condition, such as in aqueous or in gas phase. Moreover, the reactivity of the abstraction also depends on the location of \-H in the secondary structure motifs. The preferentiall \-Hs to be abstracted in ]-sheet are those immediate to the amide or carbonyl group, without involving hydrogen bonding. While in reverse turns, those are near the C-terminal of type I and near the N-terminal of type II. In general, the \-Hs in \-helix are more difficult to be abstracted than those in ]-sheet and poly-peptide in linear form. It is consistent with the trend of their bond dissociation energies. Our theoretical rate constant of N-Acetyldiglycin-methylamide (Ac(Gly)2NHCH3) in aqueous, 6.75x108 M-1sec-1 is close to the experimental observation of N-Acetyldiglycinamide (Ac(Gly)2NH2), 8.6x108 M-1sec-1.

 

 

PG3 Proteomic analyses of the manganese regulon of Neisseria gonorrhoeae

Hsing-Ju Wua, Kuan-Tin Pana, He-Hsuan Hsiaoa, Michael P. Jenningsb, Alastair G. McEwanb, Chen-Wen Yaoc and Andrew H.-J. Wanga

a Core Facilities for Proteomics Research, Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan; b School of Molecular and Microbial Sciences & Centre for Metals in Biology, The University of Queensland, Brisbane, Australia; cChinese Herbal Medicine Research Center, Tri-Service General Hospital, Taiwan

 

Neisseria gonorrhoeae is an important human pathogen which causes gonorrhoea and pelvic inflammatory disease, both of which are significant global health problems. It is a facultative aerobe with a high iron requirement and a highly active aerobic respiratory chain. These factors would suggest that this bacterium would require defense systems to respond to toxic oxygen species. In previous studies we have shown that the accumulation of manganese (Mn) and Mn(II) uptake system, MntABC, in N. gonorrhoeae protected against killing by superoxide anion, and was independent of superoxide dismutase activity. Also, investigation of a regulatory role for Mn(II) in N. gonorrhoeae has revealed that a key virulence factor, pilin, is repressed by Mn via a PerR-independent post-transcriptional mechanism. To provide a more comprehensive view of the regulatory network and its molecular mechanism, the shotgun proteomic approach,, i.e. one dimensional (1D) sodium dodecyl sulfate-polyacrylamide gel electrophoresis (1D-SDS-PAGE) coupled with 1D liquid chromatography (LC) - tandem mass spectrometry (MS/MS) and the quantitative method, i.e., isotope coded affinity tag (ICAT) were performed.

N. gonorrhoeae cells were grown in the presence and absence of Mn and cell lysates were fractionated into cytoplasmic, inner membrane and outer membrane components. These results revealed that 110 proteins are differentially regulated at the post transcriptional level under conditions of increased Mn. The Mn-regulated proteins have a broad range of functions including oxidative stress defence (i.e. superoxide dismutase (SodB), azurin, bacterioferritin), cellular metabolism, protein synthesis, RNA processing, cell division, pilin and the proteins involved in the pilus assembly, such as PilC1, PilF and PilQ. This confirms our previous study and may explain how the expression of pili was downregulated when cells were grown in the Mn supplement. Taken together, these data give us a proteomic view of Mn regulation and provided us with leads to correlate protection against oxidative stress with pilus formation and surface protein expression.