"Emir Khatipov" <ekhatipo at NOSPAMmidway.uchicago.edu> wrote:
::I think your question was mainly about whether there are other "wetlab"
:methods of determination of molecular weight of a protein. In addition to
:SDS-PAGE you used, there is also
:native electrophoresis,
That's what my boss is also saying, but this is very wrong.
Native EF has everything to do with charge and almost
nothing with size.
:gel filtration, ultracentrifugation, mass spectrometry, chemical methods,
:like Kjeldal analysis, and others.
Whta's Kjeldal analysis? Never heard of it. (Should have?)
- Dima
:"Frederic Langlois" <ye.midget.pirates.deleted.my.account at the.seven.seas>
:wrote in message news:eppz6.12265$up4.324633 at carnaval.risq.qc.ca...:> Hello.. I'm trying to figure out the different ways to calculate a
:protein's
:> mass for an assignment. In this particular case I want to know the mass of
:> the green fluorescent protein (GFP).
:>:> 1) The first method I have used is the SDS-PAGE electrophoresis with the
:low
:> range standard markers. I made a standard curve of the standards Rf value
:(Y
:> axis) and the molecular weight (X axis). I extrapolated the GFP's mass
:using
:> it's Rf value.
:>:> 2) Then I searched many databanks and found GFP's amino acid sequence. I
:> used this equation to find GFP's mass:
:>:> mass = [(n1*molecular
:>:weight1)+(n2*mol.weight2)+...(n20*mol.weight20)]/[(n1+n2+...n20-1)*33g/mol]
:>:> where 1=glycin; 2 to 20= all the other amino acids
:> n=the sum of the amino acids of each kind
:> 33g/mol=a water molecule's molecular weight (approximately)
:>:> I substrated the water molecules that are "lost" when the peptidic bonds
:are
:> made.
:>:> I converted the molecular weight in Dalton units...
:>:> 3) what are the other methods I can use to find the mass of this protein?
:>:> Thanks in advance,
:>:> Frederic Langlois
:>:>:>::
