Functions of Proteins Flashcards
How many gigabases in a human genome encodes for proteins?
out of 3.2 gigabases, only 1.1 to 1.4% encodes for proteins
What percentage of the human genome are repeated sequences?
> 50% repeated sequences which are also known as junk or parasitic elements
Elaboration and de novo Appearance of Human gene families:
What are the specific Vertebrate Abilities?
neuronal complexity, blood clotting and immune responses
Immunoglobulin domains greatly expanded: Antibodies, MHC, proteins, Antibody receptors and lymphocyte cell-surface proteins.
Elaboration and de novo Appearance of Human gene families:
What are the increases in general capabilities?
Signalling, development, apoptosis, and transcriptional control.
30 fibroblast growth factors in the Human genome, 2 in fly and worm.
906 olfactory receptor genes and pseudogenes in the human genome.
90% not previously annotated and 60% have disrupted ORF’s indicating functional loss
What are the common functions of human proteins?
Motion and Locomotion: Contractile proteins and molecular motors
Catalysis: Enzymes
Cell structure: Extracellular matrix, collagens, cellulose, vimentin, etc.
Transporters: Ca^2+ and ATPase
Ion channels: VOC, Chloride channel
Receptors and signalling proteins: GPCRs
Nutrients
Transcription factors: NF-kB, Antennapedia
What % of Human genome encodes transcription factors
6%
What % of Human genomes encodes for receptors?
5%
What does the term Proteome mean?
Term used to describe entire protein complement of a cell
Define Proteomics
Study of proteome
Define Interactome
A whole set of molecular interactions in a given cell
Define Post translation
Term used to describe entire protein complement of a cell
What is Post translation important for?
For secreted proteins and membrane-bound proteins (GPCRs)
Post translation modifications include?
Attachment of additional groups (e.g. carbohydrates)
Disulphide formation
What are the common Post-translational Modifications?
Ribosome, Phosphorylation, Glycosylation, Ubiquitination, SUMOylation, Disulfide Bond, Acetylation, Lipidation, Methylation and Hydroxylation
Post-translational modifications:
Addition of functional groups, what does this include?
Glycosylation (e.g N-linked)
Amidation of C-terminal
Palmitoylation
Post-translational modifications:
What structural changes are involved?
Enzymatic cleavage
Disulphide bond formation
Phosphorylation
Define Interactomes
An entire set of interactions inside a cell
Define Party hubs
Proteins that interact with many partners most of the time
Define Date hubs
Bind different partners, different times and places
Explain the process of Apoptosis
1) Release of cytochrome c from the mitochondria
Binds to protein Apaf-1, causing it to assemble into seven-fold rings
2) Caspases, activated by binding to a ring of CARD domains on the assembled apoptosome
Explain Ion (chloride) channels
Found in the membrane of many types of nerves
Pass through the nerve membrane, make gates allowing/blocking chloride ions.
Antibiotic Ivermectin attacks glutamate-gate chloride channels, paralysing parasitic worms
Insulin is a protein hormone, what does it do?
Carries messages which shows the amount of sugar in the blood
Made in pancreas
Secreted to blood after meals when sugar levels are high
How does insulin work in the body?
Binds to insulin receptors on the surface of liver, muscle and fat cells
Telling these organs to take glucous out of the blood, storing in the form of glycogen or fat
What is Medical insulin used for?
Diabetes mellitus treated replacing the insulin that missing in the blood (injection).
Insulin from pigs differs from human insulin
Only one amino acid, therefore, are recognised by our own cells and may be used in therapy
Human insulin amino acids are used by engineering bacteria or yeast to produce a protein identical to our own
How does insulin bind to insulin receptors?
Through a change in shape that is propagated inside the cell, activating the tyrosine kinases
Binds to the outer edge of the receptor, typically only binds to one side of the symmetrical receptor
What is a Collagen protein?
One-quarter of all of the proteins in your body is collagen
It’s a major structural protein
What does Collagen do?
Forms a molecular cable, strengthening the tendons and resilient sheets that support the skin and internal organs
Bones and teeth: Made by adding mineral crystals to collagens
provides structure to our bodies
Protecting and supporting the softer tissues and connecting them with skeleton
Define post-translational Glycosylation?
Proteins and lipids on surfaces of red blood cells, post-translationally modified with carbohydrate chains
How is blood type determined post-translational Glycosylation?
ABO blood type: Determined by the type of sugars used to build the carbohydrates
Carbohydrates built around a core of 5-13 sugars called H-antigens, ends in fructose sugar. O blood type, the story ends there.
For A and B, glycosyltransferase adds one more sugar to end.
Type A: N-acetylgalactosamine
Type B: Galactose
What is the job of an Antibody?
Circulate in the blood
Finds a foreign object, binds tightly to the surface
Acts as marker alerting the other powerful defensive mechanisms available in the immune system
100,000,000 different types of antibodies
What is the job of Motor protein Kinasin?
Walks along microtubules, dragging a cargo along
Composed of motor domain, splits ATP and converts the energy into motion and cargo binding domains, connects to object being moved
Composed of two chains
