Chapter 3-Nonenzymstic Protein Function Flashcards
What are examples of structural proteins in the human body?
Collagen, elastin, keratin, actin, tubulin
What are examples of motor proteins in the human body? 
Myosin, cilia, flagella of bacteria and sper, kinesics, Dyneins
What are examples of binding proteins?
Hemoglobin, calcium binding proteins, DNA binding proteins
What are the three families of CAM’s cell adhesion molecules?
Cadherins (glycoproteins) mediate calcium dependent cell adhesion
Integrins contain alpha and beta membrane spanning chains (bind and communicate with the extracellular matrix
Selectins bind to carbohydrate molecules that project from other cell surfaces
Name one type of immunoglobulins?
Antibodies
What are the three possible outcomes when a antibody is bound to an antigen?
Neutralization: the antibody neutralizes the antigen making the pathogen or toxin unable to exert its effects on the body
Opsonization: Marking the pathogen for destruction by other white blood cells is called
Agglutination: The antigen and antibody club together into large insoluble protein complexes that can be digested by macrophages
What is biosignaling?
The process in which cells receive and act on signals
Ion channels
Passive or active?
Up or down concentration gradient?
What molecules utilize ion channels?
Passive
Down concentration gradient
Large charged or polar molecules
What are the three types of ion channels?
Ungated
Voltage gated
Ligand gated
Ungated ion channel
Having no gates, therefore unregulated.
Voltage gated channels
Gate is regulated by the membrane potential charge near the channel
membrane depolarization causes a protein confirmational change that allows them to quickly open and then close of the voltage increases
Ligand gated channels
The binding of a specific substance or leg into the channel causes it to open and close
Ex. Neurotransmitters
Enzyme linked receptors
Contain three primary protein domains:
membrane spanning domain: that anchors the receptor in the cell membrane,
ligand binding domain: which is stimulated by the appropriate like deuces and confirmational change that activates the
catalytic domain: Often results in the initiation of a second messenger cascade
G Protein Coupled Receptor
Large family of integral membrane proteins
involved in signal transduction
they contain seven membrane spanning alpha helices.
Electrophoresis separates proteins based on what?
Subjects compounds to electric field moves them according to their charge and size
Negative to positively charged anode
Positive to negatively charged cathode
Smaller particles pass easily and large molecules migrate slower or not at all
Electrically neutral molecules migrate slower
Native Page separates compounds on what characteristic
Analyzes proteins in their native state
Compares the molecular size or charge of proteins known to be similar in size from using other analytic methods like SDS page
One useful aspects of native page is that you can recover the compound as long as you don’t use stain and stain denatures proteins
SDS Page separates compounds based on what characteristic?
Separates compounds on relative molecular size alone
The detergent SDSD disrupts all non-covalent interactions and binds to proteins and create large chains with negative net charges thereby neutralizing the proteins original charge and denaturing the proteins
Isoelsctric Focusing deprecated proteins based on what characteristic
The pI of the amino acid
Mixture of proteins placed in a gel with a pH gradient (acidic gel at the positive anode basic gel at the negative cathode neutral in the middle)
Positively charged proteins migrate towards the negatively charged cathode
negatively charged proteins migrate towards the positively charged anode.
When the protein reaches the portion of the gel where the pH=pI the protein takes on a neutral charge and stops moving.

Chromatography separate compounds based on what property?
Polarity
Components that have a high affinity for the stationary phase will hardly move while those having a high affinity for the mobile phase will migrate much more quickly.
Column chromatography separates compounds based on
Size and Polarity
Smaller/less polar move faster
Ion exchange chromatography differs from other forms of chromatography in the following ways.
beads coated c charged substances so they attract or bind compounds that have opposite charge.
Size exclusion chromatography differs from other forms of chromatography in what ways?
The beads in the columns contain tiny pores of varying sizes. Tiny compounds get stuck while larger compounds are elites first.
Affinity chromatography differs from other forms of chromatography in what ways?
Beads are coated with a receptor that binds of the protein/antibody causing the protein to be retained in the column.
Protein is eluted by washing the column with free receptor
What ways can you determine protein structure?
X-ray crystallography, nuclear magnetic resonance spectroscopy (NMR)
X-ray crystallography more popular and reliable (small dots in diffraction pattern interpreted to determine the proteins structure.
What process best analyzes small proteins?
Edman degradation uses cleavage to sequence 50-70 amino acids. Removes n terminal of amino acids in a protein then analyzed by mass spec
What process best analyzes larger proteins?
Digestion c chymotrypsin, trypsin and cyanogen bromide
Cleaves at specific amino acid residues creating smaller fragments that can be analyzed c electrophoresis/edman degradation
What ways can you determine protein concentration?
Colorimetrilly
By UV spectroscopy or through a color change reaction.
What is one way you can determine activity levels for enzymatic samples?
Color change
Three specific reactions that utilize colorimetric changes to determine protein concentration
BCA assay: bichorionic acid assay
Lowry reagent assay, Bradford protein assay
Branford is the most common because of its reliability and simplicity
General details of the Bradford Protein Assay
Proteins mixed with a blue dye. Dye is protonated and starts off green/brown. Turns blue in the process of binding to amino acids. In the process the dye gives up proteins
Increased protein concentration=darker blue color
