J. Biol. Chem., Vol. 261, Issue 20, 9102-9104, 07, 1986
Identification of sequence homology between human plasma apolipoprotein B-100 and apolipoprotein B-48
AV Hospattankar, T Fairwell, M Meng, R Ronan and HB Brewer Jr
The structural relationship between apolipoprotein B-100 (apo-B-100) and
apolipoprotein B-48 (apo-B-48) has not been elucidated. A peptide fragment
(MDB-18) of approximately 6 kDa was isolated from a tryptic digest of
apo-B-100. The sequence of the first 22 amino acids of MDB-18 was
determined by Edman degradation. A 15-residue peptide corresponding to this
sequence was synthesized by the solid-phase method and was utilized to
develop a sequence-specific polyclonal antibody. On immunoblot analysis,
the antibody recognized both intact apo-B-100 and apo-B-48. In addition,
preincubating the antibody with the synthetic peptide abolished the
recognition of both apo-B-100 and apo-B-48. These data are interpreted as
indicating that there is an amino acid sequence homology between apo-B-100
and apo-B-48. Since the MDB-18 peptide is located in the carboxyl region of
the B-100 molecule, we propose apo-B- 100 and apo-B-48 share a common
carboxyl region sequence.