Question

Net Electric Charge of Peptides A peptide has the sequence Glu His Trp Ser Gly Leu-Arg Pro Gly (a) What is the net charge of the molecule at pH 3,8 and 11? (Use $\mathrm{p} K_{\mathrm{a}}$ values for side chains and terminal amino and carboxyl groups as given in Table $3-1 .$ ) (b) Fstimate the pI for this peptide.

          Net Electric Charge of Peptides A peptide has the sequence
Glu His Trp Ser Gly Leu-Arg Pro Gly
(a) What is the net charge of the molecule at pH 3,8 and
11? (Use $\mathrm{p} K_{\mathrm{a}}$ values for side chains and terminal amino and carboxyl groups as given in Table $3-1 .$ )
(b) Fstimate the pI for this peptide.

Added by William S.

Organic Chemistry

Janice Gorzynski Smith 4th Edition

Instant Answer

Solved by Expert Qudsiya Anis

12/20/2021

Step 1

- The N-terminal amino group has a pKa of around 9.6, so at pH 3 it will be protonated and carry a positive charge. - The C-terminal carboxyl group has a pKa of around 2.3, so at pH 3 it will be deprotonated and carry a negative charge. - Glutamic acid (Glu) has Show more…

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Net Electric Charge of Peptides A peptide has the sequence Glu His Trp Ser Gly Leu-Arg Pro Gly (a) What is the net charge of the molecule at pH 3,8 and 11? (Use $mathrm{p} K_{mathrm{a}}$ values for side chains and terminal amino and carboxyl groups as given in Table $3-1 .$ ) (b) Fstimate the pI for this peptide.