... b-D-thio-galactoside (Fig. 3, lanes 2 and 3). SDS/PAGE analysisindicated that the recombinant protein was a single band of 90 kDa after purification by affinity and gel filtrationchromatography (Fig. ... 811–819.28. Lanzetta, P .A. , Alvarez, L.J., Reinach, P.S. & Candia, O .A. (1979)An improved assay for nanomole amounts of inorganic phos-phate. Anal. Biochem. 100, 95–97.29. Farahbakhsh, Z.T., Huang, ... Sigma.DNA manipulation and sequence analysisPlasmid DNA preparation, purification of DNA fromagarose gel, and restriction enzyme analysis were performedby the standard methods [23]. DNA sequence analysis,translation,...