Flashcards in Ch 3 continued Deck (20):
what atoms give rise to an NMR signal?
H1 H2 C13 N14 N15 O17 Na23 Mg25 P31 Cl35 K39
what is the nuclear overhauser effect?
an interaction between 2 nuclei that inversely proportional to the sixth power of the distance between them
when can magnetization be transferred from an excited nucleus to an unexcited one?
if the distance is less than 5 angstroms
what is NOE and what does it do?
nuclear overhauser enhancement spectroscopy allows for detecting the location of atoms relative to each other in the 3d structure of the protein.
in NOE, what does a diagnoal represent and what does the off diagonal represent?
the diagonal represents a one dimensional spectrum, the offdiagonal peaks identify pairs of protons that are less than 5 angstroms apart
what is a PDB bank
protein data bank: all structures solved through x ray chrystalography and nmr are desposited in a central data base
what can a structure teach us about an enzyme?
catalytic mechanism of an enzyme can be determined
how can knowing protein structure help with drug development
drugs can be designed to target certain proteins using a structure-guided approach
what can be learned from protein structure?
mechanism of protein-protein recognition, structural basis for disease-causing mutations
describe the structure of an antibody
4 chains: 2 heavy chains and 2 light chains. chains are linked by disulfide bonds, the heavy and light chains from the fab domain, and the 2 heavy chains for the fc domain
what does the variable region of antibodies allow?
allow antibodies to bind variety of targets
how do you make a polyclonal antibody?
inject rabbit with protein of interest, rabbits immune system generates antibodies against the injected protein, blood is taken from the rabbit and red blood cells are removed leaving clear antiserum. antiserum contains polyclonal antibodies
differentiate between polyclonal and monoclonal antibodies
polyclonal antibodies recognize the same antigen but bind to different epitopes. monoclonal antibodies are identical and recognize only one specific epitope
how would you prepare monoclonal antibodies?
combine antibody producing cell with an inmortal cancerous myeloma cell line: hybridoma. screen hybridoma for antibody of interest. propogate hybridoma through mass culture or injecting into mouse and inducing tumor growth
advantages of monoclonal antibodies (5)
large amounts can be made with tailor made specificies
can be used in affinity columns
can be used to detect small quantities of viruses such as HIV
can be used in the treatment of cancer
what is ELISA
enzyme linked immunosorbent assay
what is the main difference between indirect and sandwich elisa?
indirect elisa looks for antibody (such as presense of antibodies to hiv proteins) and sandwich elisa detects antigens (detect antigens in blood or urine)
how does western blotting work?
transfer proteins from sds page gel to a polymer sheet
add radiolabeled specific antibody
expose on photographic film
what do fluorescently labeled antibodies detect in a cell?
can stain cell with fluorescently labeled antibodies to detect the location of a protein of interest