Proteomics Flashcards
(12 cards)
1
Q
Key Words: Protein, Proteome, Proteomic, Palaeoproteomic
A
- Proteins: One or more long, folded chain of amino acids - sequences determined by DNA
- Proteome: All the proteins in a cell, tissue, or organism. Genome is fixed but proteomes of different cells/tissues vary
- Proteomics: The study of the expression of proteins in cells, organisms, and organs
- Palaeoproteomics: The study of the proteome in ancient materials
2
Q
Protein and peptides
A
- Protein: large, complex molecules comprised of 2 or more peptides
- Peptides: betweeen 2 and 50 amino acids in a linear chain
- Essential components of all living organisms
- Involved in all metabolic processes
- Structure, function, and regulation of tissues and organs
3
Q
Animo acids and genes
A
- In humans there are 23000 genes
- 75% encode for proteins
- Amino acids are the building blocks of proteins
- 20 common amino acids, 9 essential amino acids
4
Q
Palaeoproteomics vs aDNA
A
- Proteins are more likely to be preserved than DNA
- Proteins are more abundant than DNA
- Complex, multi-level structure of inter- and intra- molecular bonds
- Amino acid composition profile is only significantly altered when most of the protein has degraded
- Predicted to survive for up to 7 million years in cold environmentts (e.g. steppe Mammoth)
5
Q
Main applications of proteomics
A
- Taxonomic Identification
- Phylogeny
- Sex estimation
- Diet [Dental Calculus]
6
Q
Proteins and genes
A
- The protein contains genetic information
- Proteome is linked to the genome
- Protein production is encoded within genes
7
Q
Peptide Mass Fingerprinting
A
Taxonomic Identification
- Genomes of species differ so therefore proteomes differ too
- Different species have different abundances of peptides and different combinations of amino acid sequences
- Each species has a unique peptide mass fingerprint
ZooMS: Zooarchaeology Mass Spectrometry
- Taxonomic identification on non-diagnostic bone through sequencing of collagen type- 1
8
Q
How to identify a peptide
A
- Mass of a peptide chain is measured by mass spectromertry
- Minimally destructive technique
- 5mg of bone required
9
Q
Phylogeny
A
The history of the evolution of a species or group, especialyl in reference to lines of descent and relationships among broad groups of organisms
10
Q
Demography
A
- A different suite of proteins are found in organisms at 3 different stages of development
- Proteins can be used to indicate the age of small non diagnostic pieces of bone
11
Q
Sex determination
A
- Amelogenin gene: involved in the development of enamel
- Proteins AMELX and AMELY
- y-alle is different from x-alle
- Detection of AMLEY positively identifies an individual as biologically male
- AMELY and AMLEX found in male
- Only AMLEX in females
12
Q
Why isn’t it more widely used
A
- Species ID is only as good as the reference library
- identification of contamination: all ancient proteins should show degredation: no standardised method of identifying modern vs degraded proteins
