Fibrous Protein Flashcards
What is the most abundant fibrous protein in the human body?
Collagen
What is the typical amino acid sequence found in Collagen
Gly-Pro-Hyp
Which part of the body is type I collagen found?
Skin
Bone
Tendon
Cornea
Which part of the body is type II collagen found?
Cartilage
Intercalated disc
Which part of the body is type III collagen found?
Blood vessel
Fetal skin
Which part of the body is type III collagen found?
Blood vessel
Fetal skin
Which part of the body is type IV collagen found?
Basement membrane
Where is type VII collagen found?
Stratified squamous epithelium
Where is type IX collagen found?
Cartilage
Where is type XII collagen found?
Tendon
Ligaments
Other tissues
The presence of which amino acid dictates that the helical conformation of alpha chain cannot be an alpha helix
Proline
What is the initial polypeptide formed in the synthesis of collagen?
Procollagen
Which type of collagen is found in highly extensible tissues
Type III
Why does a lack of vitamin C cause scurvy
Because vitamin C is needed for the hydroxylation of specific proline and Lysine residues in collagen synthesis, hydroxylation of these residues enables collagen to have more hydrogen bonds hence strengthening the tripple helix structure of collagen
Lack of these hydoroxy residues leads to weak collagen structure hence weak bones and other symptoms
Which hydroxylases, hydroxlyse the lysyl and prolyl residues of the Procollagen
Lysyl hydroxylase and prolyl hydroxylase
Which stage of collagen synthesis requires vitamin C?
Hydroxylation stage
Which stage of collagen synthesis involves the cleavage of disulfide-rich terminal regions of procollagen?
The terminal cleavage
What is formed after the procollagen is cleaved of the disulfide-rich terminal regions?
Tropocollagen
Which enzyme catalyzes the deamination of lysine residues to form allysine residues in Elastin and Collagen?
Lysyl oxidase
Which syndrome is also known as brittle bone disease?
Osteogenesis imperfecta
What causes osteogenesis imperfecta?
Mutation in the genes that code for alpha 1 or alpha 2 for type I collagen
Which collagen defect causes Osteogenesis Imperfecta
Type I Collagen defect
Which specific mutation in the alpha 1 or alpha 2 genes usually causes Osteogenesis imperfecta, and why
Mutation which causes the replacement of glycine with amino acids with bulky side chains
This hinders the formation of the triple helix structure
What is dentinogenesis imperfecta?
A genetic disorder that affects tooth development
What are the major causes of Elhers-Danlos Syndrome
deficiency of collagen-processing enzymes or from mutations in the amino acid sequences of collagen types I, III, or V.
What are the two forms of Elhers-Danlos Syndrome
Classic Form
Vascular Form
What is the classic form of the Elhers-Danlos Syndrome and what is the cause
is characterized by skin extensibility and fragility and joint hypermobility, and is caused by a defects in type V collagen,
What is the cause of the vascular form of Elhers Danlos Syndrome
Defect in type III collagen
Which form of Ehlers Danlos Syndrome is the most severe
The vascular form which causes arterial ruptures
Which type of osteogenesis imperfecta is severe and is lethal in the perinatal period?
Type II
In which type of syndrome do we have the basement membrane being affected?
Alport syndrome
Elastin is rich in which two amino acids?
Proline
Lysine
Collagen is rich in which two amino acids?
Proline and hydroxyproline
In the extracellular space, what acts as the scaffold for tropoelastin deposition ?
Fibrillin
Which amino acid is responsible for cross linking in both collagen and elastin?
Lysine
The link formed between the allysyl side chains of tropoelastin polypeptides is called
Desmosine cross-link
What changes tropoelastin to Elastin
When the desmosine cross-link is formed
A mutation in what protein causes Marfan Syndrome
Fibrillin 1
What is the precursor for elastin synthesis?
Tropoelastin
Which enzyme cleaves the N and C terminals of procollagen molecules?
Procollagen peptidases
Which fibrous protein can be used for skin care?
Elastin
What inhibits elastase
alpha1-antitrypsin
Mutation in what protein is responsible for Marfan Syndrome
Fibrillin-1
What does a defiency in α1-antitrypsin lead to
it leads to unopposed elastase activity leading to emphysema
The mutation of which gene results in defective fibrillin?
FBN1
What is pectus carinatum
A disorder in which the breastbone is protruded outward
What is pectus excavatum ?
A disorder where the breastbone is sunk into the chest
Ectopia lentis
The subluxation of the lens of the eye
Arachnodactyly
Long, tapering fingers and toes
