title: Identification of a point mutation in the human insulin gene giving rise to a structurally abnormal insulin (insulin Chicago).
abstract: Both insulin gene alleles of a diabetic patient with a mutant insulin were cloned in a lambda vector and their nucleotide sequences were determined. Nucleotide sequence analysis revealed, in one allele, a C (cytidylate) to G (guanylate) transversion in the codon for phenylalanine at position 25 of the insulin B-chain. This point mutation leads to the substitution of a leucine for phenylalanine accompanied by the loss of a restriction endonuclease Mboll recognition site and the creation of a new Rsal cleavage site at this position.
mesh_terms: D000595:Amino Acid Sequence; D004262:DNA Restriction Enzymes / Q000235:genetics; D003920:Diabetes Mellitus / Q000235:genetics; D006801:Humans; D007328:Insulin / Q000031:analogs & derivatives* / Q000235:genetics*; D007962:Leukocytes / Q000032:analysis; D009154:Mutation; D010649:Phenylalanine / Q000235:genetics
chemical_list: D007328:Insulin; D010649:Phenylalanine; C031725:insulin, Leu(B25)-; D004262:DNA Restriction Enzymes