Laminin

The laminins are collagen- like glycoproteins and a component of the extracellular matrix. Laminins are found in all basal laminae, and they have binding sites for cell surface receptors. Along with collagen type IV, entactin ( nidogen ) and heparan sulfate proteoglycan perlecan which form the basement membrane laminins mentioned. Another important component of the basal lamina are fibronectin and a number of proteoglycans.

Fifteen Lamininisoformen are previously known. The laminin consists of an α -, β - and γ of a protein chain, which are composed in heterotrimeric form for each laminin. It should be noted that 5 different α chains 3 different β - chains and γ - chains were 3 different been detected.

It, however, only the following combinations of the protein chains have so far been discovered in the Lamininisoformen:

• Laminin -1: α1β1γ1 ( laminin -111 )
• Laminin -2: α2β1γ1 ( laminin -211 )
• Laminin -3: α1β2γ1 ( laminin -121 )
• Laminin -4: α2β2γ1 ( laminin -221 )
• Laminin -5: α3β3γ2 ( laminin -332 )
• Laminin - 6 α3β1γ1 ( laminin -311)
• Laminin -7: α3β2γ1 ( laminin -321 )
• Laminin -8: α4β1γ1 ( laminin -411 )
• Laminin -9: α4β2γ1 ( laminin -421 )
• Laminin -10: α5β1γ1 ( laminin - 511)
• Laminin -11: α5β2γ1 ( laminin -521 )
• Laminin -12: α2β1γ3 ( laminin -231 )
• Laminin -13: α3β2γ3 ( laminin -323 )
• Laminin -14: α4β2γ3 ( laminin -423 )
• Laminin -15: α5β2γ3 ( laminin -523 )