Proteins: Structure and Function. Proteins. Cellular Overview Functions Key Properties Core Topics Amino Acids: properties, classifications, pI Primary Structure, Secondary Structure, and Motifs Tertiary Structure Fibrous vs. Globular Quaternary Structure. Amazing Proteins: Function.
Thrombin and Fibrinogen
R-group or side-chain
C-Terminal EndSynthesis of Proteins
There are some important uncommon amino acids we shall still encounter later on.
Net charge: +1
Net charge: -1
Net charge: 0
Basic amino acids encounter later on.
Function as bases at physiological pH
Side chains with N
Acidic amino acids
Negatively charged at physiological pH
Side chains with –COOH
Predominantly in unprotonated formCharacteristics of Acidic and Basic Amino Acids
We use different “levels” to fully describe the structure of a protein.
PARALLEL encounter later on.
– Amino acids that favor α helices:
Glu, Gln, Met, Ala, Leu
– Amino acids that disrupt α helices:
Val, Thr, Ile, Ser, Asx, Pro
Modeling protein folding with Linus (George Rose) encounter later on.
An amphiphilic helix in flavodoxin: encounter later on.
A nonpolar helix in citrate synthase:
A polar helix in calmodulin:
ADVANTAGES of 4o Structures