Membrane Bound Proteins Flashcards
what do kinases (phosphotransferases) catalyse?
reversible phosphorylation of specific serine, threonine, tyrosine, histidine
what are kinases a key target for?
new anti-cancer drugs
what are the different types of integral membrane proteins?
I - VI
what do type I and II differ in?
domain orientation
what does type IV involve?
multiple PPC
what do types V and VI have?
covalent lipid anchors
how many turns do most transmembrane helices have?
6-7
in the erythrocyte glycoprotein, what does each hexagon represent?
tetrasaccharide
what does the hydropathy index tell you?
how hydrophobic AA is
neg number = hydrophilic
positive hydropathy windows for 20 residues in a row are indicative of what?
transmembrane domain
what is the hydropathy window at residue 4?
average of indivudal hydropathies from 1-7
what is the hydropathy of residue 5?
average between 2-8
what are charged residues usually found to do?
expose themselves to water
blue colour
what does helix bundling allow for?
hydrogen bonding to glucose in channel region
in e.coli lactose permease, what is the switching believed to be due to?
change in protonation in AA salt bridge according to transmembrane proton gradient
