D.M. Li, Q.Y. Liu, F. Zhao, Y. Hu, D. Xiao, Y.X. Gu, X.P. Song and J.Z. Zhang
Published: August 26, 2011
Genet. Mol. Res. 10 (3): 1789-1818
DOI: http://dx.doi.org/10.4238/vol10-3gmr1153

Cite this Article:
D.M. Li, Q.Y. Liu, F. Zhao, Y. Hu, D. Xiao, Y.X. Gu, X.P. Song and J.Z. Zhang (2011). Isolation and characterization of outer membrane proteins of Bartonella henselae using 2-D gel electrophoresis and mass spectrometry. Genet. Mol. Res. 10(3): 1789-1818. http://dx.doi.org/10.4238/vol10-3gmr1153

About the Authors:
D.M. Li, Q.Y. Liu, F. Zhao, Y. Hu, D. Xiao, Y.X. Gu, X.P. Song and J.Z. Zhang
Corresponding author: J.Z. Zhang
E-mail: Zhangjianzhong@icdc.cn

ABSTRACT
Bartonella henselae, an infectious agent causing cat-scratch disease and vasculoproliferative disorders in humans, is a fastidious facultative intracellular pathogen. The outer membrane proteins of B. henselae are key molecules that play a primary role in host-cell interactions. We isolated B. henselae outer membrane proteins, using the ionic detergent N-lauroyl sarcosine sodium salt and sodium carbonate, purification by two-dimensional (2-D) gel electrophoresis, and protein identification using mass spectrometry. Treatment with buffers containing ASB-14 and ZWITTERGENT 3-10 increased solubilization of B. henselae proteins, particularly proteins with basic pI. Three hundred and sixty-eight spots were detected from the sarcosine-insoluble outer membrane fraction; 94 distinct protein species were identified from 176 spots. In the outer membrane fraction from carbonate incubation, 471 spots were calculated and 259 spots were identified, which included 139 protein entries. There were six outer membrane proteins in the sarcosine-insoluble outer membrane fraction compared with nine outer membrane proteins from samples subjected to carbonate incubation. We used bioinformatic analysis to identify 44 outer membrane proteins by prediction of their domains and tertiary structures and documented the potential virulence factors. We established the 2-D reference maps of the outer membrane subproteome of B. henselae using the two different extraction methods, which were partly complementary to each other. Sodium carbonate extraction isolated low-abundance and basic proteins better than the lauroyl sarcosine sodium salt extraction, which enriched high-abundance porins.

Key words: Bartonella henselae; Outer membrane protein; 2-D gel electrophoresis; MS; Bioinformatics.