Figure 1.
Alignment of the amino acid sequences of LA2144 and bovine PAF-AH isoform I α1-subunit.
The alignment was generated by using ClustalW. Identical and similar amino acids were shaded. Identical amino acids were indicated by asterisks. The conserved motif Gly-Asp-Ser-Leu-Val/Ile, and the enzyme activity sites, Asp and His, were indicated in purple. Hypothetical signal peptide was boxed. Tyr195 of LA2144 was marked in red, and its relative amino acid at bovine PAF-AH isoform I α1-subunit was indicated in blue.
Table 1.
Kinetic parameters of rL-PAF-AH, human serum and the specific activity of Y195H rL-PAF-AH.
Figure 2.
As an intracellular protein, L-PAF-AH was released into the culture medium via autolysis when entering the stationary phase.
L. interrogans was grown in EMJH medium. Culture samples were obtained at 0, 30, 54, 78, 94, 103 and 130 hr, after initial inoculation. The cell densities (squares) were counted in a Petroff-Hausser counting chamber (Fisher) while the L-PAF-AH protein concentrations (triangles) in the culture supernatants were determined by ELISA. The standard deviations were in all cases below 10%. L-PAF-AH protein was further detected in selected cells crude extracts and culture supernatants (★, ☆, ▪) by mass spectrometry. ★, identified in culture supernatants; ☆, not identified in culture supernatants; ▪, identified in cells crude extracts.
Table 2.
The amino acid195, RT-PCR and specific activity of PAF-AH in ten leptospires cultured in EMJH and Korthof media.
Figure 3.
Serum PAF-AH levels of healthy human individuals and animal species (A), and the serum PAF-AH levels of normal gerbils (n = 6) on the serial 32 days (B).
Bars indicated the standard error. ★, human or animal species commonly used for experimental study of leptospirosis.
Figure 4.
Time course of pulmonary hemorrhage (A), mortality rate (B) and PAF-AH level in serum (C) of gerbils inoculated with PBS, the avirulent strain of L. interrogans serovar Lai and L. interrogans serovar Lai.
PBS, injected with PBS alone; avirulent, injected with the avirulent strain of L. interrogans serovar Lai; virulent, injected with L. interrogans serovar Lai. (A) The measurement and plot of pulmonary hemorrhage referred to Materials and Methods. (C) Avirulent a, no pulmonary hemorrhage observed in the gerbils injected with the avirulent strain of L. interrogans serovar Lai; avirulent b, pulmonary hemorrhage observed in the gerbils injected with the avirulent strain of L. interrogans serovar Lai. At indicated time, number of animals was shown under the figures. Bar indicated the standard error.
Figure 5.
PAF-AH levels in serum of patients with leptospirosis and healthy adult individuals.
Normal (n = 15), healthy human group; non-icterohaemorrhagiae (n = 18), leptospirosis patients infected by L. interrogans serogroup Pyrogenes (n = 3), Autumnalis (n = 3), Pomona (n = 3), Hebdomadis (n = 4) and Canicola (n = 5), other than L. interrogans serogroup Icterohaemorrhagiae; icterohaemorrhagiae (n = 28), leptospirosis patients infected by L. interrogans serogroup Icterohaemorrhagiae. Horizontal bars represented the mean value for each group.
Figure 6.
Blood leptospira level of eight gerbils infected by L. interrogans serovar Lai.
0 represented that leptospira was not observed. Bar indicated the standard error.