bacteria...our small factories - ? (Nov/29/2005 )

hi......i need answer to a small question:


we know that the expression of protein in prokaryotes is different than eukaryotes...


then...how it is possible to express human insulin for example in these small factories? how could it be expressed? what about the post-translational modification? what about the post-transcriptional modifications (splicing,....)?

?

are you a student, Strawberry?

sure, but why you are asking such strange question?????

because a good molecular biology or general genetics course should answer your question


when you design an expression protocol, even when you are just expressing bacterial proteins in another bacteria, you design the experiment in such a way that it will work in the system you wish to use.

for example, if you want to express a human gene in bacteria, you would use cDNA and not gDNA from human cells when making the initial clone, because the bacteria will not recognize introns...this is only one of the things that have to be considered if you want to express such a protein in its native form, and sometimes it is not possible

there are also eukaryotic expression systems (think yeast expression)

another thing to consider, for example, if your POI (protein of interest) normally makes a dimer with another protein, perhaps you could purify them separately and then mix them together...there are all sorts of tricks and you always have to test for appropriate acitivity of your protein after you have it purified, and maybe it will take several tries to get good native protein

does this make sense? your question was very broad and I am not sure if I have answered it well