Chapter 2 - Protein Structure

Primary

N terminal to C terminal in order

Secondary

Backbone Interactions

Primary

N terminal to C terminal in order

Secondary

Backbone Interactions

Secondary example

alpha helix, beta pleated sheets, random coils

Alpha Helix

interchain hydrogen bonds

Beta Pleated Sheets

interchain hydrogen bonds between carbonyl and NH group

Alpha Helix breakers

pro, gly, tyr, asn

Tertiary

sidechain interactions

Tertiary Examples

salt bonds, disulfide brindges

Hydrophilic

h2o soluable tend toward outside as protein folds

Hydrophobic

h2o insoluable tend toward inside as protein folds

Keratin

two or more alpha helix strands in a cable

Collagen

three alpha helices wound in a triple helix; stabilized by covalent bonds

Quaternary

aggregation behavior (allosteric interactions in hemoglobin)

Denatuirn Protein

Organic Solvents soluablize hydrophobic

pH disrupts salt link

Mechanical Stirring/heating disrupts noncovalent bonds

High Salt Concentration disrupts salt bonds