Protein Structure Notes (Transcript-Based) (copy)

Peptide Backbone

The part of the protein that participates in forming secondary structure; side chains do not form this structure directly.

Primary Structure

The linear sequence of amino acids in a protein, read from the N-terminus to the C-terminus.

N-terminus

The end of a protein or polypeptide chain that has a free amino group.

C-terminus

The end of a protein or polypeptide chain that has a free carboxyl group.

Secondary Structure

The local folded structures that form within a polypeptide due to hydrogen bonding within the peptide backbone.

Alpha Helix

A common type of secondary structure formed when the peptide backbone coils and stabilizes through hydrogen bonds.

Beta Pleated Sheet

A secondary structure formed by hydrogen bonds between parallel or antiparallel strands of the peptide backbone.

Hydrogen Bonding

Interactions that occur between the carbonyl oxygens and amide hydrogens in the peptide backbone, crucial for secondary structure.

Disulfide Linkage

A covalent bond formed between the sulfhydryl groups of two cysteine residues that stabilizes protein structure.

Tertiary Structure

The overall 3D shape of a protein, determined by interactions between side chains (R-groups).

Quaternary Structure

The assembly of multiple polypeptide chains into a functional protein complex.

Tyrosinase

An enzyme involved in pigmentation, indicating its enzymatic role by ending in '-ase'.

Carbohydrate Tag (CHO)

A modification that marks proteins for transport to specific cellular locations, such as the nucleus.

Lethal Factor

A proteolytic enzyme that targets kinases, disrupting cell signaling and leading to cell death.

Hydrolysis

The chemical process of splitting a large molecule into smaller pieces, such as during the action of the lethal factor on kinases.