7. (5 pts) Alpha-keratin is a very common structural protein that makes up our n

Question

7. (5 pts) Alpha-keratin is a very common structural protein that makes up our nails, hair, and in other species, makes up their horns and claws. The basis of the ou-keratin structure is a coiled coil. a) What is the handedness of the individual a-helixes, and how does that handedness compare to the overall handedness of the coiled-coil? b) What pattern distinguishes coiled-coil sequences, and which positions in that pattern are important for stabilizing the coiled-coil structure? c) What predominant type of non-covalent interaction holds the coils together?

Explanation / Answer

A. -keratin, is a type of keratin found in mammals. This protein is the principle component in hairs, horns, nails and the epidermis layer of the skin. -keratin is a fibrous structural protein, that means it conssits of amino acids that have a repeating secondary structure. The secondary structure of -keratin is very similar to that of a traditional protein -helix and forms a coiled coil right helix. Compact coiling of these monomeric right handed alfahelices gives left handed fibrous keratin. Due to its tightly wound structure, it can function as one of the strongest biological materials and has various uses in mammals, from predatory claws to hair for warmth. -keratin is synthesized through protein biosynthesis, utilizing transcription and translation, but as the cell matures and is full of -keratin, it dies, creating a strong non-vascular unit of keratinized tissue

B. As keratin contain alfa helices, and in order to maintain alfa hecal structure, there is a regular hydrogen interactions between every firxt and fourth amino acids in the peptide and form coiled coil structure. Each helix length is 5.4 A0 and it contain 3.6 Amino acids.

C. HYDROGEN INTERACTIONS ARE PREDOMINANT TYPE OF NON-COVALENT INTERACTIONS IN COILS. HYDROGEN INTERACTIONS ARE FORMED BETWEEN PARTIAL POSITIVE AND NEGATIVE CHARGES. IN ALFA HELIX, THE HYDROGEN INTERACTIONS ARE INTER CHAIN HYDROGEN INTERACTIONS

Related Questions

Navigate

• Browse (All)
• Browse 7
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.