Protein engineering Flashcards Preview

BIO2030 Biotechnology > Protein engineering > Flashcards

Flashcards in Protein engineering Deck (13)
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1

What is a protein's secondary structure?

Higher-level structures formed from backbone interactions between amino acids

2

Describe α helices

Carbonyl of one amino acid and the amino group of an amino acid 4 down the chain hydrogen bond
Turn every ~3.6 amino acids
Side chains stick out
Right-handed

3

Describe β strands/sheets

Hydrogen bonding between carbonyl and amino group across parts of the primary structure
Can be antiparallel (planar H bonding and N- and C- termini are adjacent to partner) or parallel (Staggered H bonding where N- and C- termini is adjacent)

4

Describe disulfide bonds

Links between adjacent cysteine residues in oxidising conditions
More common in extracellular proteins and eukaryotes
Stabilise structures

5

What are structural motifs?

Arrangements of multiple secondary structure elements together

6

What are active sites?

Spatial organisation of catalytic residues and ligand binding pockets to give a protein its function

7

What are fusions/deletions?

Removal of residues and domains or the addition of tags

8

What is site-directed mutagenesis?

Codon indels by mismatch PCR

9

What is directed evolution?

Mimics natural evolutionary selection with specific libraries and selection for specific protein characteristics

10

What are the pros of directed evolution?

Doesn't require detailed structural knowledge of protein of interest

11

What are the cons of directed evolution?

PCR based methods can be biased
Selection method required
Needs high-throughput assay that measures what you want to evolve

12

What are some ways to generate a library?

PCR-based methods
Primer-based methods
Random libraries (buy)
Mutagenic strains

13

What are some ways to make a protein more stable or enhance its activity?

Thermostability
Salt tolerance
Solvent tolerance
pH tolerance
Greater substrate range
Altered cofactor preference
Enantioselectivity
New chemistry