Are proteins tightly packed?

We find that the surface of a protein is never packed more tightly than its interior. This confirms results from the study by Gerstein and Chothia (1996).

Where are proteins folded and packaged?

the endoplasmic reticulum
Protein folding occurs in a cellular compartment called the endoplasmic reticulum. This is a vital cellular process because proteins must be correctly folded into specific, three-dimensional shapes in order to function correctly. Unfolded or misfolded proteins contribute to the pathology of many diseases.

Why does DNA have to be tightly packed?

These proteins are called histones, and the resulting DNA-protein complex is called chromatin. DNA is negatively charged, due to the phosphate groups in its phosphate-sugar backbone, so histones bind with DNA very tightly. Figure 1: Chromosomes are composed of DNA tightly-wound around histones.

What is responsible of protein folding in the RER?

A newly synthesized protein entering the endoplasmic reticulum (ER) undergoes a series of modifications and encounters a number of molecular chaperones and folding enzymes that all together assist its proper folding and subsequent release from the ER.

How does a protein fold?

Protein folding is a process by which a polypeptide chain folds to become a biologically active protein in its native 3D structure. The amino acids in the chain eventually interact with each other to form a well-defined, folded protein. The amino acid sequence of a protein determines its 3D structure.

What maintains the secondary structure of a protein?

Secondary structure refers to regular, recurring arrangements in space of adjacent amino acid residues in a polypeptide chain. It is maintained by hydrogen bonds between amide hydrogens and carbonyl oxygens of the peptide backbone. The major secondary structures are α-helices and β-structures.

What stabilizes secondary protein structure?

Secondary Structure This structure resembles a coiled spring and is secured by hydrogen bonding in the polypeptide chain. The second type of secondary structure in proteins is the beta (β) pleated sheet.

What determines protein stability?

The Source of Stability in Proteins The contribution each residue makes to, or takes away from, the stability of a protein is small. Thus the stability of a protein is determined by large number of small positive and negative interaction energies.