Protein Interior Amino Acid Identification
The interior of water-soluble globular proteins is shielded from the aqueous environment. This non-polar, hydrophobic environment favors the burial of hydrophobic amino acid residues to minimize unfavorable interactions with water.
Analysis of Amino Acid Residues
We need to identify the most hydrophobic amino acid among the options:
- Threonine: A polar, uncharged amino acid. Tends to be found on the surface.
- Aspartic acid: An acidic, charged amino acid. Found on the surface.
- Valine: A nonpolar, aliphatic amino acid. Highly hydrophobic.
- Histidine: A polar amino acid, which can be uncharged or positively charged depending on the pH. Tends to be found on the surface or in active sites.
Conclusion on Residue Location
Valine, being a strongly hydrophobic residue, is the most likely to be found in the protein's interior, away from the surrounding water.
Important Questions from Structure and Function of Biomolecules
- An element that is present in a nucleotide but not in a nucleoside is __________.
- Which one of the following coenzymes is utilised by alanine racemase for the conversion of L-Alanine to D-Alanine?
- Which of the following show(s) optical activity at 100 mM concentration in water?
An octapeptide composed of these L-amino acids – Lys, Thr, Ser, Met, Arg, Trp, Tyr, Glu was subjected to analyses with the following outcomes:
P. The N-terminal sequencing analysis by Sanger's method yielded 'Ser' at the N-terminus
Q. Chymotrypsin treatment gave a pentapeptide, a ‘Tyr' containing dipeptide and a free ‘Glu'
R. Cyanogen bromide treatment gave two tetrapeptides
S. Trypsin treatment gave two tripeptides and a dipeptide
Which one of the following is the correct octapeptide sequence?
- Which of the following amino acids contain(s) two chiral carbons?
