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  #1  
Old 04-25-2010
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Biochemistry Transmembrane CFTR!

The CFTR consists of single peptide chain with transmembrane segments and extracellular and intracellular regions. Which of the following peptide segments of CFTR is most likely located in a transmembrane segment?

A) Asp-Val-Leu-Thr-Glu-Lys-Glu-Ile
B) Glu-Glu-Thr-Glu-Glu-Glu-Val-Gln
C) Ile-Phe-Val-Leu-Ile-Trp-Cys-Leu
D) Lys-Ile-Lys-His-Ser-Arg-Gly-Arg
E) Ser-Thr-Gly-Ala-Gly-Lys-Thr-Ser
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Old 04-25-2010
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or to simple - choice C, assuming no Phe deletion present in 508.
or more complicated - any of other choices, amino acids 433−586 in CFTR NBD-1
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Old 04-25-2010
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it should be (C),as all amino acids are non polar.
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Old 04-25-2010
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yes ur right. C is the ans.
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Old 04-25-2010
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Default Please explain

Wait a minute
Somebody please explain for me the whole issue.
I did not understand the question neither it's answer
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Old 04-26-2010
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Quote:
Originally Posted by GNND85 View Post
Wait a minute
Somebody please explain for me the whole issue.
I did not understand the question neither it's answer
CFTR - Cystic fibrosis transmembrane conductance regulator. Mutation in CFTR leads to cystic fibrosis. In stem no word about CF.
Now only pure logic - we know that deletion of Phe in 508 leads to CF. From present choices, only C has Phe inside. So, assuming that no mutation present in transmembrane segment, what else we have to do, --> Phe is present --> choice C. May be they are non-polar on second look, but pure logic more fast .
I don't know exact order in CFTR and don't want to know, because in this segment are amino acids from 433 to 586
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Old 04-26-2010
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this is a great question!!!
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Old 05-17-2011
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Quote:
Originally Posted by just_md View Post
CFTR - Cystic fibrosis transmembrane conductance regulator. Mutation in CFTR leads to cystic fibrosis. In stem no word about CF.
Now only pure logic - we know that deletion of Phe in 508 leads to CF. From present choices, only C has Phe inside. So, assuming that no mutation present in transmembrane segment, what else we have to do, --> Phe is present --> choice C. May be they are non-polar on second look, but pure logic more fast .
I don't know exact order in CFTR and don't want to know, because in this segment are amino acids from 433 to 586
indeed better use logic with this kind of question; when I saw all the AA; I was about to have a heart attack
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