Lecture 8: Protein Structure and Function Flashcards
_____\_: Lysine residues of protein targets proteins for degradation in the proteasome
Ubiquitinoylation: Lysine residues of protein targets proteins for degradation in the proteasome
Histone Ubiquitinylation:
- H2A and H2B ubiquitinylated
- Not related to degradation
- Affects _____\_structure and __________\_
Histone Ubiquitinylation:
- H2A and H2B ubiquitinylated
- Not related to degradation
- Affects chromatin structure and gene transcription
Histone Ubiquitinylation effects:
– ______\_ alignment and segregation
– _______\_ repair
– Transcriptional response in ______\_
Histone Ubiquitinylation effects:
– Chromosome alignment and segregation
– DNA repair
– Transcriptional response in inflammation
__________: Addition of phosphate via protein Kinase
Phosphorylation: Addition of phosphate by protein kinase
_____________\_: Kinase activity affected by another kinase, which in turn affects multiple molecules of another
Kinase cascade: Kinase activity affected by another kinase, which in turn affects multiple molecules of another
Phosphorylation:
_______ charges change the structure
Can affect the binding site of ligands elsewhere on protein
Access of Substrate to the active site
Phosphorylation:
Negative charges change structure
Can affect binding site of Ligands elsewhere on protein
Access of Substrate to active site
What is the T-Loop?
Gate that covers the active binding site till it becomes negatively charged via phosphorylation
Kinase families have similar functions/roles:
- __________ across plasma membrane
- Intracellular signal amplification
- Cell cycle control
Kinase families have similar functions/roles:
- Signal transduction across plasma membrane
- Intracellular signal amplification
- Cell cycle control
The Bcr-Abl __________\_ oncogene causes chronic myelogenous leukemia (CML) and Philadelphia chromosome-positive acute lymphoblastic leukemia (ALL
This enzyme remains stuck in activated form and induces excessive proliferation of ____\_
Treatment?
The Bcr-Abl tyrosine kinase oncogene causes chronic myelogenous leukemia (CML) and Philadelphia chromosome- positive acute lymphoblastic leukemia (ALL)
The enzyme remains in activated form. Induces excessive proliferation of WBCs
Imatinib (GLEEVEC) binds to the site of tyrosine activity and prevents its activity. Served as model for other targeted therapy modalities
Role of proteins: (7)
- Enzymes
- Transport
- Contraction
- Protection
- Hormones
- Control of transcription/translation
- Structure
___________:
Binds Oxygen in Muscles
7 Helices
1 Heme w/ iron
Myoglobin:
Binds Oxygen in Muscles
7 Helices
1 Heme w/ iron
__________:
Transports Oxygen in the blood
Tetramer: Can bind with 4 molecules of oxygen, one to each ________\_
2 alpha chains and 2 beta chains
Cooperative Interaction?
Hemoglobin:
Transports Oxygen in blood
Tetramer: Can bind with 4 molecules of oxygen, one to each Porphyrin
2 alpha chains and 2 beta chains
Cooperative Interaction: Once first binds, second binds more easily_,_ and so on
Each subunit of hemoglobin is a _________ protein with an embedded ______ group
Each subunit of hemoglobin is a globular protein with an embedded heme group
In sickle cell hemoglobin ___________\_ in position 6 (in beta chain) is mutated
to ____\_. This change causes the ________\_ form of hemoglobin molecules to stick together
In sickle cell hemoglobin glutamic acid in position 6 (in beta chain) is mutated
to valine. This change causes the deoxygenated form of hemoglobin molecules to stick together
- Hemoglobin relies on negative charge of Glutamic acid to repel from one to another*
- When changed to Valine w/ no charge the molecules stick together*
______\_: Group of genetic disorders characterized by errors in metabolic pathways of heme synthesis.
Phorias: Group of genetic disorders characterized by errors in metabolic pathways of heme synthesis.
____________:
Also known as antibodies, are glycoprotein molecules produced by white blood cells. They act as a critical part of the immune response by specifically recognizing and binding to particular antigens, such as bacteria or viruses
Immunoglobulins:
Also known as antibodies, are glycoprotein molecules produced by white blood cells. They act as a critical part of the immune response by specifically recognizing and binding to particular antigens, such as bacteria or viruses
_________: Protein that aids in coagulation and protects against blood loss
Fibrin: Protein that aids in coagulation and protects against blood loss
Antibody Structure:
Shuffling of peptides allows for very specific binding of specific antigens
All of the diversity of antibody binding is attributed to changing less than a dozen proteins in the ___________\_
Antibody Structure:
Shuffling of peptides allows for very specific binding of specific antigens
All of the diversity of antibody binding is attributed to changing less than a dozen proteins in the hyper-variable region
Complementarity Determining Region (CDR_)_ = ________\_
Complementarity Determining Region (CDR_)_ = Antigen binding site
Enzymes:
- Reduce ______\_ energy of reaction
- Remain unchanged so can be re- used again and again
- Effective in ____\_ amounts
- Enzymes can cause reactions to occur up to 10 billion times easier than when no enzyme is present
Enzymes:
- Reduce activation energy of reaction
- Remain unchanged so can be re- used again and again
- Effective in small amounts
- Enzymes can cause reactions to occur up to 10 billion times easier than when no enzyme is present
________: molecule on which an enzyme acts
Substrate: molecule on which an enzyme acts
Standard chemical reaction: rate of reaction is _______\_ to the concentration of substrate
Standard chemical reaction: rate of reaction is directly proportional to the concentration of substrate
Enzyme-catalyzed reaction: rate of reaction ______\_ increase further with increasing concentration of substrate
Enzyme-catalysed reaction: rate of reaction doesn‘t increase further with increasing concentration of substrate
Saturated when the active site of all of the enzyme molecules present are occupied
__________: Inhibition or activation of an enzyme by a small regulatory molecule that interacts with the enzyme at a site other than the active site. Interacts ______\_ with enzyme
Allosteric Regulation: Inhibition or activation of an enzyme by a small regulatory molecule that interacts with the enzyme at a site other than the active site. Interacts non-covalently with enzyme
___________\_ - enzyme permanently inactivated. Example?
Irreversible inhibition - enzyme permanently inactivated.
e.g.Aspirin irreversibly inactivates the cyclooxygenase (COX) enzyme required for prostaglandin and thromboxane synthesis
_______ inhibition - the enzyme can function normally when the inhibitor is diluted or removed
Reversible inhibition - the enzyme can function normally when the inhibitor is diluted or removed
___________ Inhibition: Interferes with active site of enzyme so substrate cannot bind
Competitive Inhibition: Interferes with active site of enzyme so substrate cannot bind
__________ Inhibition: Changes shape of enzyme so it cannot bind to substrate
Non-Competitive Inhibition: Changes shape of enzyme so it cannot bind to substrate
_________\_ can be detected by measuring enzymes that leak into the blood
Tissue damage can be detected by measuring enzymes that leak into the blood
