ISSN:
0886-1544
Keywords:
intracellular matrix
;
extracellular matrix
;
covalently cross-linked matrix
;
ε-(γ-glutamic) lysine bonds
;
skeletal muscle
;
titin
;
covalently cross-linked collagen
;
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Medicine
Notes:
When skeletal, cardiac, and smooth muscle is exhaustively extracted with a protein-unfolding reagent such as 6 M guanidine HCl and a disulfide-reducing reagent such as 5% β-mercaptoethanol, a tissue ghost remains intact and retains the characteristic shape and dimensions of the tissue before extraction. In the case of chicken pectoral muscle, the tissue ghost contains 1% of the original muscle proteins. Guanidine HCl extraction followed by collagenase treatment of glycerol-extracted chicken pectoral muscle releases a clean preparation of elongated structures containing 0.2% of the original protein and representing the covalently cross-linked remnants of the muscle fibers. The material of these muscle fiber ghosts extends throughout the interior of the cell. Antibodies raised against the tissue ghosts of smooth muscle cross-react with glycerol extracted skeletal myofibrils, forming a banding pattern which coincides with the banding pattern observed when myofibrils are reacted with antibodies against titin. Titin, a large and soluble protein found in skeletal muscle, cross-reacts with our antigizzard antibody. However, amino acid analysis of the muscle fiber ghosts indicates that titin cannot be the only subunit of the insoluble polymer, but that one or more proteins with a very high glycine and alanine content and a very low basic and acidic amino acid content must also form part of the covalently cross-linked matrix. The possibility is presented that this matrix may be the basis of the superthin 2-3-nm filaments which have been observed in a variety of cell types.
Additional Material:
12 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cm.970030514
Permalink
