Analysis of a genetic mutation in an electrophoretic variant of the human lactate dehydrogenase-B(H) subunit.
An electrophoretic variant of the lactate dehydrogenase (LDH)-B(H) subunit was discovered in a patient with diabetes mellitus. His LDH activity in serum was slightly lower than normal and the LDH isozyme pattern showed an abnormal migration indicating an LDH-B subunit variant of the fast type. The LDH containing the variant subunit revealed a decreased heat stability. DNA analysis of the variant allele detected a base substitution, an A to G transition, at codon 6 (AAA-->GAA). The mutation resulted in the replacement of a lysine by a glutamic acid (K6E). The change may cause the heat instability and affect the net charge of the variant subunit, resulting in an electrophoretic LDH-B subunit variant of the fast type.
Maekawa
M
M
Department of Laboratory Medicine, Hamamatsu University School of Medicine, Japan.
Sudo
K
K
Kitajima
M
M
Matsuura
Y
Y
Li
S S
SS
Kanno
T
T
D000368:Aged; D000483:Alleles; D001483:Base Sequence; D004252:DNA Mutational Analysis; D003920:Diabetes Mellitus / Q000201:enzymology; D004591:Electrophoresis, Polyacrylamide Gel; D014644:Genetic Variation; D006358:Hot Temperature; D006801:Humans; D007527:Isoenzymes; D007770:L-Lactate Dehydrogenase / Q000235:genetics*; D008297:Male; D008969:Molecular Sequence Data; D009692:Nucleic Acid Heteroduplexes / Q000032:analysis; D017354:Point Mutation; D016133:Polymerase Chain Reaction
D007527:Isoenzymes; D009692:Nucleic Acid Heteroduplexes; D007770:L-Lactate Dehydrogenase