#Question id: 725
#Part-B Specialized Branches in Biotechnology
At 25°C values of [θ]222, the mean residue ellipticity at 222 nm, are - 33,000 and -3,000 deg cm2 dmol-1 for a polypeptide existing in α- helical (α) and β-structure (β), respectively. If this polypeptide undergoes a two-state heat-induced α-β transition, and a value of [θ]222 = -15,000 deg cm2 dmol-1 is observed at 60°C, then this observation leads to the conclusion that the α helix conversion to β- structure is:
#Question id: 727
#Part-B Specialized Branches in Biotechnology
26-residue peptide composed of alanine and leucine shows a circular dichroism (CD) spectrum characteristic of α-helix at 50°C in 5 mM phosphate buffer at pH 7.4. When the peptide solution is cooled gradually to 25°C, and the CD spectra are recorded at different temperatures, the most likely observation will be that
#Question id: 729
#Part-B Specialized Branches in Biotechnology
Which of the following is correct about the collagen triple-helix domain
a. is rich in glycine. b. is rich in proline.
c. is rich in hydroxyproline. d. is an alpha helix.
#Question id: 732
#Part-B Specialized Branches in Biotechnology
Ramachandran plots can help increase the accuracy of models derived from x-ray crystallography data. The plot below was created by measuring phi, and psi for each amino acid residue in a 2.2 A resolution crystal structure. In the plot, which excludes Gly and Pro residues, selected residues (dots) are numbered 1 through 5.
Which of the following statements can be correctly stated for this plot in reference to selected residues?
A. Residues 1 and 3 are in either B sheets
B. residue 2 is in a right-handed a helix, and residue 4 is in a left-handed a helix.
C. If residue 5 were Gly, it might be in an acceptable position in the plot
#Question id: 734
#Part-B Specialized Branches in Biotechnology
Which of the following statements is true for two different tripeptides consisting of either glycine or proline?
#Question id: 736
#Part-B Specialized Branches in Biotechnology
The most important contribution to the stability of a protein’s conformation appears to be the: