p.1
Structure and Function of Collagen and Elastin
What is collagen?
A structural protein that provides strength and support to various tissues in the body.
p.1
Collagenopathies and Genetic Disorders
Who is Dr. Bart Dzudzor?
A professional associated with the study or research of collagen.
p.2
Structure and Function of Collagen and Elastin
What are the main functions of collagen and elastin?
Collagen provides structural support, while elastin allows tissues to stretch and recoil.
p.2
Types of Collagen and Their Synthesis
What should one know about the various types of collagen?
The different types of collagen and their specific sites of synthesis.
p.2
Biosynthesis and Post-Translational Modifications of Collagen
What is involved in the biosynthesis of collagen?
The process includes synthesis and post-translational modifications.
p.2
Collagenopathies and Genetic Disorders
What are collagenopathies?
Genetic disorders that affect collagen structure and function.
p.3
Structure and Function of Collagen and Elastin
What are collagen and elastin?
Common fibrous proteins of the extracellular matrix that serve structural functions in the body.
p.25
Structure and Function of Collagen and Elastin
What is the effect of hyp residues on collagen chains?
They greatly increase the potential for hydrogen bonding between chains.
p.64
Structure and Function of Collagen and Elastin
What are proteoglycans?
A special class of glycoproteins that are heavily glycosylated (95%).
p.64
Structure and Function of Collagen and Elastin
What do proteoglycans consist of?
A core protein with one or more attached glycosaminoglycan chains.
p.34
Elastin Structure and Function
How is tropoelastin modified to form elastin?
It is highly cross-linked to form an insoluble complex.
p.20
Structure and Function of Collagen and Elastin
Where does hydrogen bonding occur in collagen?
Between the amide N of glycine residues in the central axis and the carbonyls of adjacent chains.
p.40
Types of Collagen and Their Synthesis
What types of collagen are mentioned?
Types I, II, III, V, IX, and X.
p.40
Collagen Fiber Formation and Cross-Linking
What structural feature reflects the periodic composition of collagen fibers?
The cross striated structure of collagen fibers.
p.23
Clinical Presentation of Ehlers-Danlos Syndrome
What did James Lind recommend to prevent scurvy?
The inclusion of greens, fresh vegetables, and ripe fruits in the diet.
p.9
Structure and Function of Collagen and Elastin
What is the structure of Collagen IV's amino-terminal domain?
It has a short non-helical amino-terminal domain.
p.10
Structure and Function of Collagen and Elastin
How many collagen molecules coil together to form a superhelix?
Three collagen molecules.
p.39
Collagen Fiber Formation and Cross-Linking
What role do telopeptides play in collagen structure?
They participate in covalent crosslinking.
p.25
Biosynthesis and Post-Translational Modifications of Collagen
What are hyp and pro in the context of collagen?
They are amino acids that contribute to the structure of collagen.
p.21
Collagen Fiber Formation and Cross-Linking
What type of bonding occurs between a glycine residue and a proline residue of different chains?
Inter-chain hydrogen bonding.
p.44
Ehlers-Danlos Syndrome
What is Ehlers-Danlos syndrome (EDS)?
A heterogeneous group of generalized connective tissue disorders resulting from inheritable defects in the metabolism of fibrillar collagen molecules.
p.17
Structure and Function of Collagen and Elastin
What is the structural unit of collagen?
Tropocollagen, a supercoil made up of 3 helices.
p.21
Collagen Fiber Formation and Cross-Linking
What is the significance of inter-chain hydrogen bonding in collagen?
It contributes to the stability and structure of collagen fibers.
p.11
Collagen Fiber Formation and Cross-Linking
What is the structural form of collagen?
Collagen forms a 3-stranded collagen superhelix.
p.16
Biosynthesis and Post-Translational Modifications of Collagen
What is the role of 5-hydroxylysine (HyLys) in collagen?
It serves as a site for glycosylation.
p.34
Elastin Structure and Function
What is elastin primarily composed of?
Soluble tropoelastin protein containing primarily glycine and valine, along with modified alanine and proline residues.
p.23
Clinical Presentation of Ehlers-Danlos Syndrome
Who was James Lind?
A Scottish physician who identified remedies for scurvy.
p.10
Structure and Function of Collagen and Elastin
What is the structure of each collagen molecule?
Each molecule is composed of a left-handed helix.
p.14
Types of Collagen and Their Synthesis
What is the primary amino acid composition of collagen?
35% Gly, 11% Ala, 21% Pro and Hyp.
p.55
Collagenopathies and Genetic Disorders
What is the consequence of decreased Lysyl Oxidase activity in Menkes disease?
Defective collagen formation.
p.31
Elastin Structure and Function
Where are elastic fibers composed of elastin found?
In the lungs, walls of large arteries, and elastic ligaments.
p.58
Structure and Function of Collagen and Elastin
What is a key physical property of collagen?
It has great tensile strength.
p.57
Disorders Related to Elastin Degradation
What chronic exposure occurs in the normal lung regarding elastin?
Alveoli are exposed to low levels of neutrophil elastase from activated and degenerating neutrophils.
p.58
Structure and Function of Collagen and Elastin
What are the main components that collagen is a part of?
Fascia, cartilage, ligaments, tendons, bone, and skin.
p.42
Collagenopathies and Genetic Disorders
What is Ehlers-Danlos syndrome?
A group of 10 different collagen deficiency diseases.
p.10
Structure and Function of Collagen and Elastin
Are collagen helices classified as alpha helices?
No, they are not alpha helices.
p.19
Collagen Fiber Formation and Cross-Linking
What is the appearance of collagen fibers in an electron micrograph?
They appear as long, thin, and wavy structures.
p.4
Structure and Function of Collagen and Elastin
What dictates the types and organization of collagen molecules in the body?
The structural role collagen plays in a particular organ.
p.3
Structure and Function of Collagen and Elastin
Where are collagen and elastin found in the body?
In skin, connective tissue, blood vessel walls, and the sclera and cornea of the eye.
p.4
Structure and Function of Collagen and Elastin
What type of collagen structure is found in tendons?
Tight parallel structure.
p.36
Biosynthesis and Post-Translational Modifications of Collagen
Where are collagen precursors formed?
In fibroblasts, osteoblasts of the bone, and chondroblasts of cartilage.
p.19
Structure and Function of Collagen and Elastin
What is the primary function of collagen in the skin?
To provide strength and support.
p.12
Structure and Function of Collagen and Elastin
What is the unique secondary structure of collagen?
It is distinct from an alpha helix.
p.58
Structure and Function of Collagen and Elastin
What role does collagen play in tissues and organs?
It contributes to their stability and maintains structural integrity.
p.37
Biosynthesis and Post-Translational Modifications of Collagen
What is required for the hydroxylation of lysine and proline?
α-ketoglutarate, O2, ascorbic acid, and Fe2+ as a cofactor.
p.37
Biosynthesis and Post-Translational Modifications of Collagen
What is glycosylation in collagen synthesis?
The addition of galactose and glucose to some hydroxylysine residues.
p.7
Types of Collagen and Their Synthesis
Which collagens are classified as fibril-forming?
Collagens I, II, III, V, and X.
p.48
Biosynthesis and Post-Translational Modifications of Collagen
What causes Type I Osteogenesis Imperfecta?
Decreased production of α1 and α2 chains.
p.6
Types of Collagen and Their Synthesis
In which tissues are Type III collagen fibers prevalent?
In more distensible tissues, such as blood vessels.
p.11
Types of Collagen and Their Synthesis
What is the composition of collagen in terms of amino acids?
Collagen is composed of 35% Gly, 11% Ala, and 21% Pro and hydroxyPro.
p.43
Collagenopathies and Genetic Disorders
How many mutations have been identified in collagen-related genes?
More than 1,000 mutations.
p.44
Ehlers-Danlos Syndrome
What can cause Ehlers-Danlos syndrome?
Deficiency of collagen-processing enzymes or mutations in the amino acid sequences of collagen types I, III, or V.
p.20
Structure and Function of Collagen and Elastin
Which amino acids are often involved in the hydrogen bonding of collagen?
Proline and hydroxyproline.
p.9
Structure and Function of Collagen and Elastin
What is the function of the carboxyl-terminal globular NC1 domain in Collagen IV?
It is highly conserved and involved in polymerization.
p.17
Structure and Function of Collagen and Elastin
What type of helix is the collagen helix?
Left-handed and not an alpha-helix.
p.37
Biosynthesis and Post-Translational Modifications of Collagen
Which enzymes are involved in the hydroxylation process?
Lysyl-5-hydroxylase and prolyl-4-hydroxylase.
p.46
Clinical Presentation of Ehlers-Danlos Syndrome
What is a common characteristic of the skin in patients with Ehlers-Danlos Syndrome?
Skin is velvety and fragile, with severe scarring from minor trauma.
p.45
Collagenopathies and Genetic Disorders
What mutation is associated with Type IV EDS?
Mutation in COL3A1, leading to abnormal collagen III.
p.5
Biosynthesis and Post-Translational Modifications of Collagen
What results from variations in the amino acid sequence of the α chains?
Structural components with slightly different properties.
p.36
Biosynthesis and Post-Translational Modifications of Collagen
What happens to processed mature mRNA after transcription?
It is exported to the cytosol for translation by ribosomes.
p.6
Types of Collagen and Their Synthesis
Where are Type I collagen fibers primarily found?
In supporting elements of high tensile strength, such as tendons and cornea.
p.6
Types of Collagen and Their Synthesis
What is unique about the structure formed by Types IV and VII collagen?
They form a three-dimensional mesh rather than distinct fibrils.
p.6
Types of Collagen and Their Synthesis
What major structure do Type IV collagen molecules contribute to?
Basement membranes, by assembling into a sheet or meshwork.
p.55
Collagenopathies and Genetic Disorders
What is Menkes disease?
A condition caused by impaired copper absorption and transport due to defective Menkes protein.
p.11
Biosynthesis and Post-Translational Modifications of Collagen
What is gelatin derived from?
Gelatin is derived from collagen.
p.14
Structure and Function of Collagen and Elastin
What type of secondary structure does collagen have?
A unique secondary structure distinct from an alpha helix.
p.44
Ehlers-Danlos Syndrome
What is the most clinically important mutation in Ehlers-Danlos syndrome?
Mutations found in the gene for type III collagen.
p.45
Collagenopathies and Genetic Disorders
Which genes are commonly mutated in 40% to 50% of EDS patients?
COL5A1 or COL5A2 (type V collagen gene).
p.3
Structure and Function of Collagen and Elastin
What is a key characteristic of collagen and elastin as fibrous proteins?
They are water insoluble and provide tensile strength.
p.55
Collagenopathies and Genetic Disorders
What are the clinical manifestations of Alport Syndrome?
Defective glomerular filtration, eye problems (e.g., retinopathy, lens dislocation), and sensorineural deafness.
p.46
Clinical Presentation of Ehlers-Danlos Syndrome
Which joints are commonly hypermobile in Ehlers-Danlos Syndrome?
Shoulders, patellae, and ankles.
p.45
Clinical Presentation of Ehlers-Danlos Syndrome
What serious complications are seen in Type IV EDS?
Arterial, intestinal, and uterine rupture.
p.56
Collagenopathies and Genetic Disorders
Why are children with Epidermolysis bullosa referred to as 'butterfly children'?
Because their skin is very delicate and fragile, similar to that of a butterfly.
p.53
Collagenopathies and Genetic Disorders
Which gene is mutated in Marfan syndrome?
Fibrillin-1 gene on chromosome 15q21.
p.36
Biosynthesis and Post-Translational Modifications of Collagen
Which residues are hydroxylated during collagen biosynthesis?
Selected proline and lysine residues.
p.48
Clinical Presentation of Ehlers-Danlos Syndrome
When does Osteogenesis Imperfecta typically present?
In early infancy with fractures secondary to minor trauma.
p.6
Types of Collagen and Their Synthesis
What structures are Type II collagen molecules restricted to?
Cartilaginous structures.
p.42
Collagenopathies and Genetic Disorders
Who is an example of a person with Ehlers-Danlos syndrome?
The 'India-rubber man' of circus fame.
p.16
Types of Collagen and Their Synthesis
What amino acids make up approximately 30% of collagen residues alongside Glycine?
Proline or Hydroxyproline (HyPro).
p.55
Collagenopathies and Genetic Disorders
What are some symptoms of Menkes disease?
Brittle kinky hair, growth retardation, and hypotonia.
p.31
Elastin Structure and Function
What happens to elastic fibers when they are stretched?
They can be stretched to several times their normal length.
p.55
Collagenopathies and Genetic Disorders
What causes Alport Syndrome?
Defective synthesis and processing of type IV collagen.
p.59
Structure and Function of Collagen and Elastin
What type of molecule is collagen?
An insoluble glycoprotein (protein + carbohydrate).
p.9
Collagen Fiber Formation and Cross-Linking
How does Collagen IV polymerize?
It polymerizes into a disulfide-bonded polygonal network via tetramerization and dimerization.
p.59
Types of Collagen and Their Synthesis
What is the primary structure of collagen polypeptide represented by?
The sequence G – X – A, where G is glycine, X is proline or hydroxyproline, and A is an amino acid.
p.32
Elastin Structure and Function
Which amino acids are primarily found in elastin?
Glycine, alanine, and valine.
p.5
Types of Collagen and Their Synthesis
What is the composition of type I collagen?
Two α1 chains and one α2 chain (α1²α2).
p.46
Clinical Presentation of Ehlers-Danlos Syndrome
What is a notable feature of the fingers in Ehlers-Danlos Syndrome?
Patients may have 'double-jointed' fingers.
p.38
Biosynthesis and Post-Translational Modifications of Collagen
What is the effect of oxidation and deamination of hydroxylysine in collagen synthesis?
It has a net oxidative effect and forms covalent cross-links.
p.38
Biosynthesis and Post-Translational Modifications of Collagen
Which enzyme catalyzes the oxidation and deamination of hydroxylysine?
Lysine oxidase (or catalase).
p.8
Types of Collagen and Their Synthesis
Where is Type I collagen primarily distributed?
Bone, dermis, tendon, ligaments, and cornea.
p.18
Collagen Fiber Formation and Cross-Linking
What type of linkages are present in mature collagen?
Extensive covalent cross linkages between individual collagen molecules.
p.29
Collagenopathies and Genetic Disorders
What is Lathyrism?
A condition characterized by abnormalities of bones, joints, and blood vessels.
p.19
Collagen Fiber Formation and Cross-Linking
What does an electron micrograph of collagen reveal?
The detailed structure and organization of collagen fibers.
p.20
Structure and Function of Collagen and Elastin
What type of bonding is absent in collagen helices?
Intra-helical hydrogen bonding.
p.60
Structure and Function of Collagen and Elastin
What forms a triple-helical collagen molecule?
Three helical polypeptide units twist together.
p.42
Osteogenesis Imperfecta and Its Variants
What is osteogenesis imperfecta?
A condition characterized by abnormal (fragile) bone formation in human babies.
p.14
Structure and Function of Collagen and Elastin
What is the helical structure of collagen?
A left-handed helical structure with three residues per turn.
p.32
Elastin Structure and Function
What is the composition of tropoelastin?
A linear polypeptide composed of about 700 amino acids, primarily small and nonpolar.
p.57
Disorders Related to Elastin Degradation
What can destroy elastin in alveolar walls?
Proteolytic activity of neutrophil elastase if unopposed by α1-AT.
p.58
Structure and Function of Collagen and Elastin
How does collagen contribute to development?
It plays an important role in tissue and organ development.
p.53
Collagenopathies and Genetic Disorders
What type of disorder is Marfan syndrome?
A connective tissue disorder affecting the skeleton, heart, and eye.
p.7
Types of Collagen and Their Synthesis
What does FACIT stand for?
Fibril-associated collagens.
p.53
Clinical Presentation of Ehlers-Danlos Syndrome
What is a common eye-related issue in Marfan syndrome?
Subluxation of lenses, typically upward and temporally.
p.33
Elastin Structure and Function
What forms a desmosine cross-link in elastin?
Three allysyl side chains plus one unaltered lysyl side chain from the same or neighboring polypeptides.
p.11
Structure and Function of Collagen and Elastin
What is the primary structure of collagen?
Collagen has a distinct tertiary and quaternary structure.
p.34
Elastin Structure and Function
What role does elastin play in the body?
It is a major protein component of tissues that require elasticity, such as arteries, lungs, bladder, skin, and elastic ligaments and cartilage.
p.14
Types of Collagen and Their Synthesis
What is the repeating tripeptide sequence in collagen?
Gly - X - Y, where X is often Pro and Y is often Hyp.
p.9
Structure and Function of Collagen and Elastin
What is the repeating sequence found in Collagen IV?
A long Gly-X-Y repeat domain with numerous small interruptions.
p.45
Clinical Presentation of Ehlers-Danlos Syndrome
What are the main characteristics of Ehlers-Danlos Syndrome (EDS)?
Hypermobile joints, hyperextensible skin, and fragile tissues susceptible to trauma.
p.22
Clinical Presentation of Ehlers-Danlos Syndrome
What symptoms did Jacques Cartier describe in his men suffering from scurvy?
Loss of strength, purple spots on skin, rotten gums, and falling teeth.
p.45
Collagenopathies and Genetic Disorders
What is the genetic mutation associated with Type VI EDS?
Mutation in lysyl hydroxylase.
p.52
Osteogenesis Imperfecta and Its Variants
Do Types V through VII of Osteogenesis imperfecta have collagen I mutations?
No, they do not have collagen I mutations but have a similar phenotype.
p.56
Structure and Function of Collagen and Elastin
What is the role of Type VII collagen in the skin?
It forms structural links between the epidermis basement membrane and the fibrillar collagen in the upper dermis.
p.36
Biosynthesis and Post-Translational Modifications of Collagen
What is the first step after the synthesis of the prepro-α chain?
It is targeted into the lumen of the RER for hydroxylation.
p.7
Types of Collagen and Their Synthesis
What are anchoring fibrils collagens used for?
To anchor structures in the extracellular matrix.
p.7
Types of Collagen and Their Synthesis
What is the function of basement membrane collagens?
They provide support and anchorage for epithelial cells.
p.18
Structure and Function of Collagen and Elastin
What can be seen as collagen fibers in the electron microscope?
Bundles of 3-stranded supercoils of tropocollagen.
p.43
Collagenopathies and Genetic Disorders
What are collagenopathies?
Genetic diseases resulting from defects in collagen fiber synthesis.
p.43
Collagenopathies and Genetic Disorders
What can result from defects in collagen fiber synthesis?
An inability of collagen to form fibers properly.
p.31
Elastin Structure and Function
What is elastin?
A connective tissue protein with rubber-like properties.
p.43
Collagenopathies and Genetic Disorders
How many genes are involved in collagen types related to collagenopathies?
22 genes coding for 12 collagen types.
p.44
Ehlers-Danlos Syndrome
Which collagen types are associated with Ehlers-Danlos syndrome mutations?
Collagen types I, III, or V.
p.17
Structure and Function of Collagen and Elastin
How many amino acid residues does each collagen helix consist of?
Approximately 1000 amino acid residues.
p.37
Biosynthesis and Post-Translational Modifications of Collagen
What initiates the synthesis of pre-procollagen?
Chains of pre-procollagen are synthesized on ribosomes.
p.32
Elastin Structure and Function
What is elastin synthesized from?
A precursor called tropoelastin.
p.4
Structure and Function of Collagen and Elastin
What is the structure of collagen in the cornea?
Stacked transparent structure.
p.56
Clinical Presentation of Ehlers-Danlos Syndrome
What is a common symptom of patients with Dystrophic Epidermolysis Bullosa (DEB)?
Severe blistering of the skin.
p.7
Types of Collagen and Their Synthesis
What are the main classifications of collagens?
1. Fibril-forming collagens (I, II, III, V, X), 2. Fibril-associated collagens (FACIT), 3. Network-forming collagens, 4. Anchoring fibrils collagens, 5. Transmembrane collagens, 6. Basement membrane collagens, 7. Other collagens with unique function.
p.38
Collagen Fiber Formation and Cross-Linking
What process forms collagen fibrils from tropocollagen molecules?
Self-assembly or polymerization.
p.49
Osteogenesis Imperfecta and Its Variants
What recent development has been observed in some patients with Type II Osteogenesis imperfecta?
Some have lived into young adulthood.
p.49
Osteogenesis Imperfecta and Its Variants
What genetic mutations are commonly found in patients with severe Osteogenesis imperfecta?
Mutations in the gene for pro-α1 or pro-α2 chains of type I collagen.
p.36
Biosynthesis and Post-Translational Modifications of Collagen
How is collagen transported to the extracellular matrix?
Through secretary vesicles and exocytosis.
p.35
Elastin Structure and Function
What is the result of the action of lysyl oxidase on lysine in elastin?
The spontaneous formation of desmosine cross-links.
p.12
Structure and Function of Collagen and Elastin
What is the repeating tripeptide sequence in collagen?
Gly - X - Y, where X is often Pro and Y is often Hyp.
p.14
Structure and Function of Collagen and Elastin
What does collagen form?
A three-stranded superhelix.
p.22
Clinical Presentation of Ehlers-Danlos Syndrome
What happens to the gums in individuals with scurvy?
They become rotten, causing flesh to fall off and teeth to loosen.
p.58
Structure and Function of Collagen and Elastin
What important roles does collagen play in cellular processes?
Cell differentiation, polarity, and movement.
p.59
Collagen Fiber Formation and Cross-Linking
What role do proline and hydroxyproline play in collagen?
They provide stiffness to the polypeptide chain.
p.57
Disorders Related to Elastin Degradation
What is the role of α1-antitrypsin in the lungs?
It is the most important inhibitor of neutrophil elastase.
p.46
Clinical Presentation of Ehlers-Danlos Syndrome
What joint issues are frequently observed in Ehlers-Danlos Syndrome patients?
Frequent sprains or subluxation of larger joints, either spontaneously or after slight trauma.
p.46
Clinical Presentation of Ehlers-Danlos Syndrome
What is a serious complication associated with the vascular subtype of Ehlers-Danlos Syndrome?
Spontaneous visceral or arterial ruptures.
p.7
Types of Collagen and Their Synthesis
What type of collagens form networks?
Network-forming collagens.
p.49
Osteogenesis Imperfecta and Its Variants
What is the effect of common mutations in Osteogenesis imperfecta on collagen structure?
They replace glycine residues with amino acids that have bulky side chains, preventing proper triple-helical conformation.
p.8
Types of Collagen and Their Synthesis
Where is Type XI collagen primarily distributed?
Cartilage and vitreous body.
p.52
Osteogenesis Imperfecta and Its Variants
What is Osteogenesis imperfecta (OI)?
A genetic disorder characterized by fragile bones.
p.10
Structure and Function of Collagen and Elastin
What type of superhelix is formed by the coiling of collagen helices?
A right-handed superhelix.
p.31
Elastin Structure and Function
What occurs when the stretching force on elastic fibers is relaxed?
They recoil to their original shape.
p.52
Osteogenesis Imperfecta and Its Variants
What are the characteristics of bone in Osteogenesis imperfecta?
Decreased number of trabeculae and cortical thickness, leading to wormian bone.
p.56
Collagenopathies and Genetic Disorders
What causes Epidermolysis bullosa?
Mutation, defect, or deficiency of Type VII collagen.
p.59
Biosynthesis and Post-Translational Modifications of Collagen
What amino acids constitute about 1/6 of the total collagen sequence?
Proline and hydroxyproline.
p.60
Structure and Function of Collagen and Elastin
What characteristic does the triple-helical collagen molecule have regarding bending and rotation?
It has some bending stiffness and does not undergo rotation.
p.53
Collagenopathies and Genetic Disorders
What type of genetic inheritance does Marfan syndrome follow?
Autosomal dominant; 25% new mutations.
p.49
Osteogenesis Imperfecta and Its Variants
What are common causes of death in patients with Type II Osteogenesis imperfecta?
Respiratory problems, often leading to pulmonary hypoplasia.
p.38
Collagen Fiber Formation and Cross-Linking
What stabilizes collagen fibrils during their formation?
Cross-linkage between adjacent tropocollagen molecules.
p.7
Types of Collagen and Their Synthesis
What are other collagens with unique functions?
Collagens that do not fit into the other categories and have specialized roles.
p.63
Types of Collagen and Their Synthesis
What are the two main types of collagen mentioned?
Fiber forming collagen and nonfibrous collagen.
p.5
Types of Collagen and Their Synthesis
How many types of collagen are included in the collagen superfamily?
More than 25 collagen types.
p.5
Structure and Function of Collagen and Elastin
What is the approximate length of the α chains in collagen?
About 1,000 amino acids long.
p.22
Role of Hydroxylation in Collagen Stability
What is the significance of hydroxylation in collagen?
It is crucial for collagen stability, and its defect leads to scurvy.
p.37
Collagen Fiber Formation and Cross-Linking
What is formed during the assembly of α-chains in procollagen?
Disulfide bonds between registration peptides at both ends of the pre-procollagen.
p.5
Types of Collagen and Their Synthesis
How are various types of collagen formed?
By combining different α chains.
p.53
Collagenopathies and Genetic Disorders
What is the role of fibrillin in the body?
It is a glycoprotein that forms a sheath around elastin.
p.36
Biosynthesis and Post-Translational Modifications of Collagen
What is the role of transfer vesicles in collagen biosynthesis?
They transfer procollagen polypeptide to the Golgi for further modification.
p.49
Osteogenesis Imperfecta and Its Variants
What is the result of improperly formed collagen in Osteogenesis imperfecta?
Collagen is structurally abnormal.
p.12
Structure and Function of Collagen and Elastin
What type of helical structure do alpha chains of collagen adopt?
A left-handed helical structure.
p.56
Collagen Fiber Formation and Cross-Linking
What happens when there is a deficiency in Type VII anchoring fibrils?
It impairs the adherence between the epidermis and the dermis.
p.32
Elastin Structure and Function
What role do glycoprotein microfibrils, such as fibrillin, play in elastin synthesis?
They function as a scaffold for the deposition of tropoelastin.
p.32
Elastin Structure and Function
What happens to some lysyl side chains of tropoelastin?
They are oxidatively deaminated by lysyl oxidase, forming allysine residues.
p.48
Clinical Presentation of Ehlers-Danlos Syndrome
What are common features of Osteogenesis Imperfecta?
Retarded wound healing and a kyphotic appearance due to a rotated and twisted spine.
p.49
Osteogenesis Imperfecta and Its Variants
What are the physical characteristics of patients with severe Osteogenesis imperfecta?
Numerous fractures, severe bone deformity, small stature, and underdeveloped lungs.
p.57
Disorders Related to Elastin Degradation
What genetic defects can lead to emphysema and cirrhosis?
Defects in α1-antitrypsin.
p.48
Osteogenesis Imperfecta and Its Variants
What is Type I Osteogenesis Imperfecta called?
Osteogenesis imperfecta tarda.
p.8
Types of Collagen and Their Synthesis
Where is Type II collagen found?
Cartilage, vitreous body, and nucleus pulposus.
p.48
Osteogenesis Imperfecta and Its Variants
How may Osteogenesis Imperfecta be suspected prenatally?
If ultrasound detects bowing or fractures of long bones.
p.49
Osteogenesis Imperfecta and Its Variants
What is another name for Type II Osteogenesis imperfecta?
Osteogenesis imperfecta congenita.
p.8
Types of Collagen and Their Synthesis
Where is Type III collagen primarily distributed?
Skin, vessel wall, and reticular fibers of most tissues (lung, liver, spleen, etc.).
p.53
Clinical Presentation of Ehlers-Danlos Syndrome
What are common physical characteristics of individuals with Marfan syndrome?
Tall with long extremities and hypermobile joints.
p.53
Clinical Presentation of Ehlers-Danlos Syndrome
What are some specific signs associated with Marfan syndrome?
Long tapering fingers and toes, aortic incompetence, and dissecting aortic aneurysm.
p.7
Types of Collagen and Their Synthesis
What is the role of transmembrane collagens?
They span the cell membrane and are involved in cell signaling.
p.8
Types of Collagen and Their Synthesis
Where is Type V collagen found?
Lung, cornea, bone, fetal membranes, together with Type I collagen.
