METHODS AND RESULTS: A three-step procedure comprising acetone fractionation followed by fast protein liquid chromatography (FPLC) resulted in a 30-fold purification. The purified enzyme had a molecular mass of 300 +/- 5 kDa as determined by gel filtration. It is probably a tetramer containing two different subunits with molecular masses of 93 +/- 1 kDa and 59 +/- 0.5 kDa, as determined by SDS-PAGE.
CONCLUSION: The deduced N-terminal amino acid sequences of the two subunits revealed no significant similarity between them and other proteins when compared to the data bases of EMBL and SWISS-PROT, indicating that this could be the first report on N-terminal amino acid sequence of F6PPK.
SIGNIFICANCE AND IMPACT OF THE STUDY: The data from this study will be used to design oligonucleotide probe specific for bifidobacteria and to study the gene encoded F6PPK.
OBJECTIVES: This study aimed at describing the immunochemical properties of the BN allergens. Comparative studies between 3 commercially available sources (according to the country of origin) of BN were also made.
METHODS: Crude extracts of commercially available processed BN from Sarawak (Malaysia), Thailand, and Indonesia and fresh unprocessed BN from the caves of Sarawak were obtained by means of aqueous extraction. Specific IgE toward these sources were determined by using fluorescence allergosorbent tests (FASTs). Cross-reactivity studies between the 3 sources of commercially available processed BN were carried out by means of FAST inhibition. Immunochemical characterization by means of IgE immunoblot, periodate treatment, and heat stability studies were carried out on fresh unprocessed BN from Sarawak.
RESULTS: Serum from allergic patients showed differences in IgE binding to the 3 sources of commercially available BN, with the highest levels of specific IgE recorded with the Sarawak source (P