Simple purification and secondary structure evaluation of Sendai virus neuraminidase water soluble fragment

We have developed a quick and simple method to purify the water soluble fragment of Sendai virus neuraminidase (cHN). We used the trifluoperazine (TFP) as detergent because of its ability to selectively solubilize the HN (Baiocchi et al., (1988) FEBS Lett. 238, 171-174). Here we describe conditions by which trypsin produces the cHN from the TFP treated virions. The cHN is further purified by size exclusion chromatography and it fully retains the neuraminidase activity and the allosteric inhibitory site as described in (Dallocchio et al., (1991) Biochem. Int. 25, 663-668). Both circular dichroism (CD) spectra, analyzed by deconvolution methods and secondary structure prediction were used to assess the secondary structure of cHN.