Question

Which of the following amino acid sequences for a segment of an integral protein is likely to correspond to a transmembrane segment of the protein? Explain.

A) LSTTEVAMHTTTSSSVSKSY

B) SQTNDTHKRDTYAATPRA

C) VSEISVRTVYPPEEETGE

D) ITLIIFGVMAGVIGTILLI

E) YGIRRLIKKSPSDVKPLP

Answer 1

E) YGIRRLIKKSPSDVKPLP

out of four segment this segment can span the membrane because it contains maximum nuber of hydrophobic amino acids.

as we know the membrane is hydrophobic in nature , so only hydrophobic amino acids can traversed the membrane.

hydrophobic amino acids : valine, alanine, tyrosine, tryptophan , methionine,isoleucine, lysine , phenylalanine, proline, glycine.

this segment contain 10 hydrophobic amino acids which is maximum among all the four segment.