Determine the net charge (to the nearest integer) on the following peptide at pH5 AND pH 12. Estimate the isoelectric point (pl) for this peptide: H2N-Leu-Gly-Lys-Glu-COOH

the overall, net ionic charge on this peptide at pH = 7 would be: Cys - Ala - Glu-Arg - Met - Ser

A HEPTAPEPTIDE that punctures the bacterial cell wall has just been recently isolated from the venom gland of a frog. Amino acid analysis of the peptide reveals the following information below: (NOTE: when the sequence is not known, a comma separates the amino acids) Hydrezine Acid Hydrolysis (6 N HC) at 10 C Heptapeptide (2) Arg. Pro, Phe, Tyr, Ala, Lys 2,4 dinitrafluerobenzene DNP-Phe Lys and modified free amino acids Peptide 1 (Ala, Lys) Cleovage with Trypsin, then chrometogrophy Peptide 2 (Pro, Arg, Tyr) Peptide 3 (Phe, Arg) Phe Peptide 4 (Arg. Tyr) Clevege with Chymetrypsin, then cromategrphy Peptide 5 (Lys, Pro, Ala, Arg)

if the tetrapeptide shown in the binding site above (Gly-Ser-His-lle) were in an aqueous solution at pH=6.2, what fraction of peptide molecules would have a +1 charge?

Which of the following amino acids would you least expect to find on the surface of a water-soluble protein? Explain I Serine Glutamat Lysime Threonine