Molecular evidence for human alpha 2-HS glycoprotein (AHSG) polymorphism.
Alpha 2-HS glycoprotein (AHSG) is a human plasma glycoprotein that exhibits genetic polymorphism on isoelectric focusing (IEF). To identify the origin of two common alleles, AHSG*1 and *2, we examined nucleotide exchanges in the gene. AHSG cDNA was obtained by RT-PCR from poly(A) RNA of seven liver tissue samples and subcloned into a plasmid vector. After sequencing, we found six single nucleotide differences in comparison with the originally reported sequence. In particular, the nucleotide substitutions of C to T at amino acid position 230 and C to G at position 238 were common among the samples exhibiting phenotype 2-1 or 2. Since these substitutions might give rise to a NlaIII site and a SacI site, respectively, for the potential AHSG*2, we analyzed these substitutions by PCR-RFLP using genomic DNA of 68 individuals. The result was consistent with the IEF analysis of the corresponding serum, indicating that AHSG*1 was characterized by ACG (Thr) at position 230 in exon 6 and ACC (Thr) at position 238 in exon 7, and that AHSG*2 was characterized by ATG (Met) at position 230 and AGC (Ser) at position 238.
Osawa
M
M
Tokai University School of Medicine, Department of Forensic Medicine, Kanagawa, Japan. osawa@is.icc.u-tokai.ac.jp
Umetsu
K
K
Ohki
T
T
Nagasawa
T
T
Suzuki
T
T
Takeichi
S
S
D000595:Amino Acid Sequence; D001483:Base Sequence; D001798:Blood Proteins / Q000096:biosynthesis / Q000235:genetics*; D003001:Cloning, Molecular; D003062:Codon; D017931:DNA Primers; D015252:Deoxyribonucleases, Type II Site-Specific; D005838:Genotype; D006801:Humans; D007438:Introns; D008099:Liver / Q000378:metabolism; D017354:Point Mutation; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D012150:Polymorphism, Restriction Fragment Length; D011994:Recombinant Proteins / Q000096:biosynthesis; D060749:alpha-2-HS-Glycoprotein
C556354:AHSG protein, human; D001798:Blood Proteins; D003062:Codon; D017931:DNA Primers; D011994:Recombinant Proteins; D060749:alpha-2-HS-Glycoprotein; C048422:endodeoxyribonuclease NlaIII; D015252:Deoxyribonucleases, Type II Site-Specific