Ascaris lumbricoides and Ascaris suum: Comparative proteomic studies using 2-DE coupled with mass spectrometry

Abstract

Roundworms of the genus Ascaris comprise species of medical (A. lumbricoides) and veterinary (A. suum) importance. Despite the economic importance, public health impact, and worldwide prevalence both parasites still have a controversial taxonomy and their proteomes are poorly described in databases. In the present study, high-resolution two-dimensional polyacrylamide gel electrophoresis (2-DE) coupled with MALDI-TOF/TOF MS was used to characterize and contrast proteomic profiles of adult female A. lumbricoides and A. suum. Approximately, 3-fold higher protein spots were obtained in the present study compared to traditional method, and more than 630 and 750 protein spots were reproducibly detected among the 6 gels examined (3 gels for each of A. lumbricoides and A. suum). The peptide mass finger printings (PMFs) were acquired successfully for 17 from 22 differential 2-DE spots, corresponding to 12 unique proteins. Among them, 2 Asu-enriched and 3 Alu-specific proteins were found in A. lumbricoides; and 6 Asu-enriched and 1 Alu-specific proteins were found in A. suum. Functional analysis revealed low level of difference among differentially expressed proteins of the two nematode species, while the 1 species-specific protein of A. suum was different from that of A. lumbricoides. The proteomic patterns of A. lumbricoides and A. suum provide proteomic evidence that these two taxa are very closely related. This work indicates that the combined 2-DE and MALDI-TOF/TOF MS approaches employed in the current study allow the identification of proteins whose expression is different between Ascaris species.