ECM-PART 3 Flashcards
describe the structure of elastic fibres
Core made of elastin and microfibrils (rich in fibrillin, a protein)
mutations in fibrillin-1 are associated with which syndrome?
Marfan’s syndrome
what are the effects of Marfan’s syndrome
.Affects skeletal, ocular and cardiovascular system
. Predisposed to aortic ruptures
.Arachnodactyly (spider fingers)
Describe the structure of elastin
Hydrophobic region and alpha-helical region rich in lysine and alanine.
Lysine chains are covalently cross linked
Describe the properties of laminin
.A multi adhesive glycoprotein
. Hetrotrimeric consisting of of an alpha, beta and gamma chain
. Self associate+ interact with other matrix components e.g type IV collagen
congenital muscular dystrophy can arise from an absence of ……
alpha 2 chain in lamnin 2
symptoms of muscular dystrophy include
.hypotonia (decreased muscle tension), deformed joints
describe fibronectin
multi adhesive protein linked by DISULPHIDE BONDS.
in what 2 forms can fibronectin exist
.insoluble fibrillar matrix
. soluble plasma protein
describe the roles of fibronectins (4)
.embryogenesis, tissue repair, regulate cell adhesion+migration, blood clotting
what are proteoglycans?
core proteins covalent attached to one or more glycosaminoglycan chains (GAG)
describe the structure of glycosaminoglycans /GAG
.repeated disaccharide units
.sulfated/carboxylated hence HIGH NEGATIVE charge
what are the different type of proteoglycans
Basement membrane proteoglycans : e.g. perlecan
Aggregating proteoglycans (interact with hyaluronan): e.g. aggrecan
Small leucine-rich proteoglycans: e.g.decorin
Cell surface proteoglycans: e.g. syndecans 1-4
what is hyaluronan?
A GAG with high degree of polymerisation
unsulfated
.takes up large volume
what is the role of hyaluronan
protecting cartilaginous joints from surface damage
