Polyclonal antibodies (pAbs) to riboflavin carrier protein (RCP) purified f
rom human amniotic fluid were raised in two rabbits, These pAbs apart from
recognizing the parent antigen, reacted significantly with chicken RCP as w
ell. When all the 212 octapeptides overlapping by one amino acid residue an
d covering the entire primary amino acid sequence of chicken RCP immobilize
d on polyethylene rods mere probed with rabbit anti-human RCP antibodies, i
t was found that these antibodies recognize five epitopic sequences (residu
es 37-42, 73-76, 133-140, 174-176 and 200-207) in chicken RCP primary struc
ture common to both the rabbits. In addition, the antisera from the two ind
ividual animals also recognized additional epitopes characteristic to that
particular animal. The reactivities of these antigenic determinants have be
en confirmed with polyclonal anti-human RCP sera by using synthetic peptide
s harbouring these chicken RCP sequences in inhibition ELISA. This high lev
el of immunological similarities among linear epitopes observed may reflect
the degree of conservation of local conformations among linear antigenic d
eterminants shared by the two evolutionarily distant homologous proteins, (
C) 1999 Academic Press.