Filamentous Hemagglutinin (FHA)
Filamentous Hemagglutinin (FHA) from Bordetella pertussis
FHA is supplied in 50 mM Sodium phosphate (pH 8), 0.5 M NaCl, 50% glycerol at a desired concentration of 0.1-0.5 mg/ml.
Filamentous hemaglutinin (FHA) is a major adhesin of B. pertussis and is a component of most acellular pertussis vaccines. FHA is produced from a 367-kD precursor which undergoes several post-translational maturations. The first 71 amino acids comprise a signal peptide, which is removed by proteolysis. A C-terminal 130-kD portion is additionally removed during the maturation and secretion of the 220-kD N-terminal region that is traditionally referred to as FHA.
The mature 220 kD FHA is purified from the culture supernatant of Bordetella pertussis (Tohama I strain).
Store at -20°C. To insure uniformity, it is recommended that the FHA suspension be thawed on ice for 10-15 min and then mixed by swirling or inversion of the tube. It should be noted that FHA is highly susceptible to proteolysis and care should be taken to minimize prolonged storage at >0°C.
Protein concentration is determined by Bradford assay method using bovine serum albumin as standard.
>90% corresponding to the full-length 220 kD FHA. Three additional minor bands of 140, 125, and 100 kD are observed by SDS-PAGE analysis. These minor bands are presumed to be degradation products of the full-length polypeptide as these bands have been noted to increase after storage of the protein at >0°C.
The FHA preparation exhibits strong hemagglutination activity when tested with sheep erythrocytes.