Topic 4 Flashcards
1
Q
Phosphorylation, Acetylation
A
- alters stability/ signalling
2
Q
Glycosylation
A
- affects protein folding
- secreation
- solubility
- binding to other biomolecules
3
Q
Myristolyation, farnesylation
A
- alters location
4
Q
Lipoproteins
A
- binds lipids
5
Q
Metalloproteins
A
- bend metal ions
6
Q
Hemoproteins
A
- have an attached heme group
7
Q
Examples of Covalent Modifications of Proteins
A
- can change protein funtion
1. linking a fatty acid to the side chain of a cys
2. adding a sugar to the side chain of an asn
3. adding a phosphoryl group to a ser side chain
8
Q
Protein-ligand Binding
A
- assume binding is reversible
- proteins contain sites which ligans specifically bind and form a “complex” with a protein
- binding occurs by multiple weak + a few strong forces (leads to specificity)
9
Q
Dissociation Constants
A
- high affinity = tight binding = small Kd
10
Q
Myoglobin
A
- consits of 8 alpha helices plus 1 heme prosthetic group
- oxygen-binding protein
- facilitates oxygen diffusion through tissues
(transports O via the Fe in heme)
11
Q
Hemoglobin
A
- complicated with 4 subunits ( 2 aplha, 2 beta)
- each subunit has a heme group
- similar to myoglobin in their secondary/ tertiary structure
12
Q
2 States of Hemoglobin
A
- Deoxy
- Oxy
13
Q
Deoxy State
A
- t state (tense)
- low affinity
- cannot find oxygen very well
14
Q
Oxy State
A
- r state (relaxed)
- high affinity
15
Q
Structure Proteins Collagen
A
- most abundant protein in animals
- form strong/insoluable fibers in extracellular matrix
- connects + strengthens tiessues
- 28 members in the collagen protein family
- have characteristic triple-helical structure
- job: give support to animals/ strengthen bones
