抄録
A 3.7 kb cDNA sequence encoding human erythrocyte type AMP deaminase (AMPD-3) has been determined by the screening of human spleen cDNA library and by some techniques utilizing polymerase chain reaction (PCR). The cDNA contains an open reading frame of 2301 by which encodes 767 amino acids chain resulting in 89 kDa protein. The homology to human muscle type AMP deaminase showed 64% identity at the nucleotide level in the area of open reading frame, and 60% similarity at the deduced amino acid level.
From the analysis of the entire codi n g region of the mutant genes using RT-PCR and direct sequencing, a point mutation of C to T resulting in a single amino acid substitution of Arg to Cys was detected in both two B-cell lines derived from complete deficiency of human erythrocyte type AMP deaminase. The analysis for genomic DNA demonstrated that two individuals with complete deficiency were homozygous for the detected mutation, and two individuals with partial deficiency were heterozygous.
