The expression of myosin light chains and tropomyosin in human muscle biopsies with histochemical type 1 and type 2 fiber deficiency.
Two-dimensional gel electrophoresis (2DE) was used to compare the protein composition of human muscle biopsies that were shown by histochemical staining to be deficient in either type 1 or type 2 fibers. Distinct quantitative differences were found in the myofibrillar protein composition of muscle from a 43-year-old woman with proximal limb weakness that showed almost total absence of type 1 fibers and muscle from a 2.5-year-old girl with congenital myopathy in which there was severe lack of type 2 fibers. These data indicate that human type 1 and type 2 muscle fibers express distinct isoforms of myosin light chains and alpha-tropomyosin.
Giometti
C S
CS
Biological, Environmental, and Medical Research Division, Argonne National Laboratory, IL 60439-4833.
Danon
M J
MJ
D000328:Adult; D001706:Biopsy; D002648:Child; D015180:Electrophoresis, Gel, Two-Dimensional; D005260:Female; D006801:Humans; D009132:Muscles / Q000378:metabolism / Q000473:pathology*; D009218:Myosins / Q000378:metabolism*; D009220:Myositis / Q000378:metabolism / Q000473:pathology; D009468:Neuromuscular Diseases / Q000378:metabolism / Q000473:pathology; D014335:Tropomyosin / Q000378:metabolism*
D014335:Tropomyosin; D009218:Myosins