Apolipoprotein B: the Ag(a1/d) immunogenetic polymorphism coincides with a T-to-C substitution at nucleotide 1981, creating an Alu I restriction site.
Short cDNA fragments covering the entire coding region for apolipoprotein (apo) B have been cloned in the pING expression vector. A monoclonal antibody specific for the Ag(d) epitope on apo B has been used, together with the expressed apo B peptides, to locate this epitope to a stretch of 26 amino acids. Sequencing of this region from several genomic DNAs of known Ag(a1/d) genotype showed a single T-to-C substitution at nucleotide 1981, creating an Alu I restriction site and resulting in a val to ala residue change in the corresponding peptide (at position 591 in the mature protein). Southern blots, using the Alu I restriction endonuclease and a short probe for this region of the cDNA, showed perfect correspondence between the restriction fragment length polymorphism and the Ag(a1/d) immunochemical polymorphism in all 17 persons examined.
Wang
X B
XB
Department of Chemistry and Biochemistry, University of California, Los Angeles 90024.
Schlapfer
P
P
Ma
Y H
YH
Bütler
R
R
Elovson
J
J
Schumaker
V N
VN
D001055:Apolipoproteins B / Q000235:genetics* / Q000276:immunology; D001483:Base Sequence; D000939:Epitopes / Q000235:genetics*; D006801:Humans; D011110:Polymorphism, Genetic; D012150:Polymorphism, Restriction Fragment Length
D001055:Apolipoproteins B; D000939:Epitopes