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Table 3 Components of the basement membrane: See Figure 2

From: The central role of vascular extracellular matrix and basement membrane remodeling in metabolic syndrome and type 2 diabetes: the matrix preloaded

Component Constituent Chains Molecular Composition Function
Type IV Collagen: alpha 1(IV), alpha 2(IV)
alpha 3(IV)
alpha 4(IV)
alpha 5(IV)
Three alpha chains
Structure:
Polygonal shaped
Network structure Provides a structural-lattice base for the attachment of other BM macromolecules such as HSPG, laminin, enactin and Fn.
Perlecan:
Heparan sulfate proteoglycan (HSPG):
Proteoglycan (PG)
Polypeptide chain, side chains of GAGs Protein Core GAG side chains Highly anionic sulfated.
Structure:
Multiple globular protein core with multiple polypeptide chains. See figure 2.
Electrostatic charge important for filtering. Especially in renal glomerulus.
Enactin – Nidogen: [31]
Structural – Adhesive Glycoprotein
Single polypeptide chain Structure:
Dumbbell-shaped sulfated glycoprotein
Bridges Laminin and Type IV collagen.
Important in assembly of the BM and changes in permselectivity properties.
Fibronectin (Fn):
Structural – Adhesive Glycoprotein
Two polypeptide chains connected by two disulfide bridges. Structural glycoprotein One of the most primitive ECM macromolecules: The first to be deposited in the embryo. Parallel to V-shaped joined by two disulfide bonds. Connecting cells with other components of the ECM, which integrates the cell into a functional unit. Very important in wound healing.
Laminin:
The most abundant glycoprotein in BMs. Structural – Adhesive Glycoprotein
CABLIN: NEW
Capillary Basement membrane lamina
A, B1, B2
First unique protein of the capillary basement membrane
One A and two B chains. Structure: Cruciform shape
Rod like structure found only in the lamina rara of capillaries
Cell attachment Assembly of the BM Stabilization of type IV Collagen
Cell-matrix attachment providing stability to the basement membrane
  1. See Figure 2