Nonenzymatic Protein Function and Protein Analysis Flashcards
Structural Proteins definition and examples
Compose the cytoskeleton, anchoring proteins, and
much of the extracellular matrix. The most common
structural proteins are collagen, elastin, keratin, actin,
and tubulin. They are generally fibrous in nature.
Motor Proteins and examples
Have one or more heads capable of force generation
through a conformational change. They have catalytic
activity, acting as ATPases to power mvmt. Common
applications include muscle contraction, vesicle mvmt
within cells, and cell motility.
Give Examples of Motor Proteins
myosin, kinesin, and dynein.
Binding Proteins
Bind a specific substrate, either to sequester it in the
body or hold its concentration at steady state
G Protein-Coupled
Receptors
GPCR has a membrane-bound protein called the GProtein
(a, b, y subunits). The 1st messenger ligand
initiates the 2nd messenger and the cascade response
Cell adhesion molecules
Allow cells to bind to other cells or surfaces.
Cell adhesion molecules: Cadherins
Calcium dependent glycoproteins that
hold similar cells together.
Cell Adhesion
Molecules (CAM): Integrins
Have two membrane-spanning chains and
permit cells to adhere to proteins in the extracellular
matrix.
Cell Adhesion
Molecules (CAM): Selectins
Allow cells to adhere to carbohydrates on
the surfaces of other cells and are most commonly
used in the immune system.
Antibodies
Immunoglobulins, Ig. Used by the immune system to
target a specific antigen, which may be a protein on
the surface of a pathogen or a toxin. The variable
region is responsible for antigen binding.
Electrophoresis
Uses a gel matrix to observe the migration of proteins in
responses to an electric field
Native PAGE:
: Maintains the protein’s shape, but results are difficult to
compare because the mass / charge ratio differs for
each protein.
SDS-PAGE
Denatures the proteins and masks the native charge so
that comparison of size is more accurate, but functional
protein cannot be recaptured from the gel.
Isoelectric
Focusing:
Separates proteins by their isoelectric point (pI); the
protein migrates toward an electrode until it reaches a
region of the gel where pH = pI of the protein
Chromatography
Separates protein mixtures on the basis of their affinity
for a stationary phase or a mobile phase
