which of the following modifications of an endogenous pharmacologically active peptide would be most likely to slow the metabolism of peptide,thus decreasing its clearance and increasing its half life?
a.administering peptide with enteric coating
b.decreasing no of aa in the peptide
c.ensuing a free amino grp at N termianal
d.ensuing a free carboxyl grp a tcarboxy terminal
e.substituting a D for L amino acid
anybody i couldnt get it.thanks.only something which will make protien less water soluble will decrease clearance.which will do that?
e.substituting a D for L amino acid ?
thanks okt3,thats the answer given,can you please explain.
i think i found the explanation,in physio kaplan notes it says:
To be transported a substance must have a certain chemical structure.Generally ,only natural isomer will be transported e.g D glucose but not L glucose.
that means,if a substance wil not be transported across then wil not be metabolised and half life increase.
junaid_08, it is not easy to explain however some study showed that:
Clearance for D-phenylalanine was greater than for the L-enantiomer in chronic renal failure
http://www.springerlink.com/content/t5vm4g3723402802/
Keep looking for better explanations and will post if i found one
Good luck
thanks okt3,
you are welcome, thanks for posting the answer from kapaln
Everything for usmle is in kaplan notes and qbank, it is a matter of your hyppocampus keeping in the right place for the right time. I remmember reading about glucose transport but can not recall where exactly in physio notes.
Thanks again