Question

Elastin molecules are crosslinked to each other by

A) hydrogen bonds between hydroxylysines and hydroxyprolines.
B) covalent bonds between lysines.
C) covalent bonds between prolines.
D) hydrophobic interactions between hydroxyprolines and glycines.
E) peptide bonds between glycines.

Answer 1

Elastin molecules are crosslinked by covalent bonds between lysins, specifically through desmosome cross-links, which provide elastin with its rubber-like elasticity.

Step-by-step explanation:

Elastin molecules are crosslinked to each other through a specific type of covalent bond. These cross-links are critical for providing the protein with its elastic properties. Elastin is primarily made up of glycine, alanine, and valine, which are small and nonpolar amino acids. It also contains a significant amount of proline and lysine. The elastin network is formed through a process where some of the lysis residues are oxidatively deaminated to create aldehyde-containing ally sine residues. Then, three of these ally Syl residues and one unaltered lysis come together to form desmosome cross-links. This interconnection is covalent in nature, and it helps to produce the rubber-like elasticity characteristic of elastin. Therefore, the correct answer for the crosslinking of elastin molecules is by covalent bonds between lysine (B).