Article Figures & Data
Figures
- Fig. 1.
Detection of LppC protein in E. coliJM109(pLPP2) by Western blotting (A) and zymography (B). The results were obtained from sodium dodecyl sulfate–12% polyacrylamide gel electrophoretograms of whole-cell extracts (equivalent to ∼6 × 108 cells/slot) from JM109(pLPP2) (lanes 1 and 3) and JM109 (plasmid-free control, lanes 2 and 4) reacted, after blotting, with a 1:1,000 dilution of affinity-purified polyclonal antibodies to LppC (A) or, without blotting, with phosphatase substrate, BCIP (B). Lane S contained marker proteins, with molecular masses indicated on the left.
- Fig. 2.
lppC-directed specificp-nitrophenyl phosphate-hydrolyzing activity ofE. coli JM109(pLPP2) outer-membrane protein in citrate buffer of different pH values.
- Fig. 3.
Gapped sequence alignment (17) of theS. equisimilis LppC (5),S. pyogenes LppA (12a), F. meningosepticum OlpA (EMBL database accession no. Y12759 ),H. pylori HP1285 (18), H. influenzaeHel (6), and E. coli AphA (16) proteins. Amino acids conserved in at least two-thirds of the proteins are in inverse font and were used to formulate a consensus sequence. Different degrees of shading indicate aligned amino acids with similar contributions to secondary structure. Note that the LppA sequence is still preliminary and incomplete at the N terminus.
Tables
- Table 1.
Specific acid phosphatase activity of whole cells and cell membranes of the indicated S. equisimilis and E. coli strains as measured by the release of pNP from p-nitrophenyl phosphate
Strain pNP release froma: Whole cells Membrane proteins H46A 3.23 ± 0.20 9.90 ± 0.33 H46AlppC::pLPP10 0.41 ± 0.05 0.36 ± 0.10 JM109 (pLPP2) 11.72 ± 0.16 119.43 ± 4.13 JM109 0.79 ± 0.08 0.56 ± 0.11 ↵a Data are the mean values and standard errors from three to six independent experiments. For whole cells, values are expressed as {pNP [micromole milliliter−1minute−1 (OD600)−1]}, and for membrane proteins, values are expressed as [pNP (micromole milliliter−1 minute−1milligram−1)].
