Western blotting analysis of the beta-hexosaminidase alpha- and beta-subunits in cultured fibroblasts from cases of various forms of GM2 gangliosidosis.
OBJECTIVE
The GM2 gangliosidoses are a group of genetic disorders caused by the accumulation of ganglioside GM2 in neuronal cells. We examined the alpha- and beta-subunits of beta-hexosaminidases by a non-radioisotopes detecting system to evaluate whether it was a useful method for understanding of the pathophysiologies of GM2 gangliosidoses.


METHODS
We investigated the alpha- and beta-subunits of beta-hexosaminidases in cultured fibroblasts from cases of various forms of GM2 gangliosidosis by means of Western blotting and a chemiluminescence detection system.


RESULTS
In a patient with infantile Tay-Sachs disease [HEXA genotype, Int5-SA(g-1-->t)/Int5-SA(g-1-->t)], the mature alpha-subunit was undetectable. In a patient with infantile Sandhoff disease (HEXB genotype, C534Y/C534Y), the mature beta-subunit was deficient. However, a small amount of the mature beta-subunit was detected in a patient with adult Sandhoff disease (HEXB genotype, R505Q(+I207V)/R505Q(+I207V)), which may have resulted in the residual enzyme activity and mild clinical course. Normal amounts of alpha- and beta-subunits were detected in a patient with GM2 activator deficiency.


CONCLUSIONS
This method is easy and sensitive for detecting target proteins, and is useful for clarification of the pathophysiologies of GM2 gangliosidoses.
Utsumi
K
K
The Second Department of Internal Medicine, Nippon Medical School, Bunkyo-ku, Tokyo, Japan. utsumi_kouichi/med2@nms.ac.jp
Tsuji
A
A
Kase
R
R
Tanaka
A
A
Tanaka
T
T
Uyama
E
E
Ozawa
T
T
Sakuraba
H
H
Komaba
Y
Y
Kawabe
M
M
Iino
Y
Y
Katayama
Y
Y
D000328:Adult; D000906:Antibodies; D015153:Blotting, Western; D002478:Cells, Cultured; D005260:Female; D005347:Fibroblasts / Q000737:chemistry* / Q000166:cytology; D020143:Gangliosidoses, GM2 / Q000378:metabolism* / Q000473:pathology*; D054818:Hexosaminidase A; D054819:Hexosaminidase B; D006801:Humans; D007223:Infant; D008163:Luminescent Measurements; D008297:Male; D012497:Sandhoff Disease / Q000378:metabolism / Q000473:pathology; D012867:Skin / Q000166:cytology; D013661:Tay-Sachs Disease / Q000378:metabolism / Q000473:pathology; D001619:beta-N-Acetylhexosaminidases / Q000032:analysis* / Q000276:immunology
D000906:Antibodies; D054818:Hexosaminidase A; D054819:Hexosaminidase B; D001619:beta-N-Acetylhexosaminidases