Fibrous Proteins + Keratin Flashcards
Name the 3 fibrous proteins
Keratins, Fibroin and Collagen
Keratins are what
Alpha helical proteins, cross linked by disulphide proteins
Fibroin are what
B conformation
Collagen has what
Triple helix
Characteristic of
1) alpha helix
2) B conformation
3) Collagen triple helix
1) Tough, insoluble protective structure of varying hardness and flexibility
2) Soft, flexible filaments
3) High tensile strength, without stretch
Alpha Keratins are part of what broader family
Intermediate filament, cell cytoskeleton
Hair consists of what
Fibrils
Fibrils consist of what
even smaller fibres twisted around each other
Each fibre consists of what
2 alpha helical polypeptides that are parallel and coiled
How is the overall strength of the fibre strengethened
Due to the super twisting
The super twisted fibre is what handed
left (opposite to individual helices)
The surface where the two alpha helices touch in the fibre are made up of what residues
Hydrophobic, R groups meshed together in a regular interlocking pattern
Alpha Keratin is rich in what hydrophobic residues
Alanine, Valine, Leucine, Isoleucine, Methonine, Phenylaline
Intertwining of 2 helical polypeptides is what structure
Quarternary
What stabilises the quaternary structure in alpha keratin
disulphide bonds
