1. A polypeptide sequence (shown below) has been identified from a function-unkn

Question

1. A polypeptide sequence (shown below) has been identified from a function-unknown membrane protein. Using the polarity scale of amino acid residues (from the table in lecture note) to predict transmembrane helices in this polypeptide. (Hint, use a window of 20 amino acid residues to plot hydropathy index of the polypeptide).

FYSLHFLLPFVISIMVMVHLVFLHDKGSVNPLGNQNHSTKISFHPYFTWKDIVGVFVVLVVLMLAVFFLPRFL

2. Calculate free energy (G) for transporting 3 moles of Ca2+ from inside to outside of a typical cell. (Using Ca2+ concentrations given in today's lecture note; T = 298k; R = 1.987x10-3 kcal/mol/deg; membrane potential (V) = -50 mV (inside negative); Faraday constant = 23.1 kcal/V/mol).

Explanation / Answer

answer for the first question ;

From 6 th amioacid that is phenyalanine to 18 th aminoacid is the one heilx region ,which consists of hydrophobic regions buried inside the transmemberane .Another Helix is present from the 48th aminoacid to 69th aminoacid is the another helix .

answer for the second question;

Delta G is equal to [Z }[ F] {Vm}

Z for calicium is 2, F is 23.1 ,V is -50mV .2 x 23.1 x -50 which is equal to -2310

so delta G for the calicium is -2310 k cal mol.

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.