Chapter 9: Tubules/Filament

Table 9.1 Intermediate filaments and matrix components


Filament Type
Molecular weight in K daltons
Protein
Tissue
Tonafilaments
40 - 68
Cytokeratins
Keratinizing and non-keratinizing epithelia; mesothelium
Glial filaments
51
Glial fibrillary acidic protein
Astroglia, Bergmann glia
Desmin filaments
53
Desmin
Skeletal, cardiac and smooth muscle
Vimentin filaments
53.5
Vimentin
Mesenchyme derived cells and tissues
Neurofilaments
68,160,200
Neurofilaments triplet proteins
Neurons of the central and peripheral nervous system

Matrix Component
Distribution
Features
Interstitial collagen type 1
skin, bone, dentin, tendon, cornea
presence of 2 chain, less than 10 hydroxylysines/chain, 0.1% carbohydrate
Interstitial collagen type 2
cartilage, vitreous body, notochord
1% carbohydrate, greater than 10 hydroxylysines/chain
Interstitial collagen type 3
as type 1, prominent in fetal skin, arteries, amniotic membrane, not in bone or tendon
presence of cysteine, high levels of hydroxyproline,glycine, histidine
Basement membrane collagen type 4
basement membranes (lamina densa)
greater than 20 hydroxylysines/chain, high 3-hydroxyproline, low alanine and arginine
Collagen type 5
associated with membraneous structures
slightly larger than 21(1), 0.3% 3-hydroxyproline
Fibronectin
loose connective tissue matrix, basement membranes, body fluids

Laminin
basement membranes (lamina rara)
ordered polypeptide structures (-chain, -sheet, disulfide knot)
Tropoelastin-Elastin
elastic fibres
high content of alanine, valine, glycine contains hydroxyproline, dross-linking
Microfibrillin


Proteoglycans


Glycosaminoglycans, sulfated proteoglycans, hyaluronic acid



Cell Biology Laboratory Manual
Dr. William H. Heidcamp, Biology Department, Gustavus Adolphus College,
St. Peter, MN 56082 -- cellab@gac.edu