BIOINORGANIC CHEMISTRY A Short Course Second Edition

PROTEINS 31

Figure 2.1 Zwitterions of nonpolar hydrophobic amino acids at physiological pH.

+H 3 NC

H

H

COO- +H 3 NC

H

CH 3

COO- +H 3 NC

H

CH

H 3 C CH 3

COO-

+H 3 NC

H

CH

H 2 C CH 3

H 3 C

COO- +H 3 NC

H

CH 2

CH

H 3 C CH 3

COO- +H 3 NC

H

H 2 C

CH 2

S

CH 3

COO-

+H 3 NC

H

CH 2

COO- +H 2 NC

H

CH 2

H 2

C

H 2 C

COO-

glycine, Gly, G alanine, Ala, A valine, Val, V

isoleucine, Ile, I leucine, Leu, L methionine, Met, M

phenylalanine, Phe, F proline, Pro, P

Figure 2.2 Zwitterions of polar neutral amino acids at physiological pH.

HN

+H 3 NC

H

CH 2

cysteine, cys, C

asparagine, Asn, N tryptophan, Trp, W glutamine, Gln, Q

Serine, Ser, S threonine, Thr, T

+H 3 NC

H

CH 2

C

H 2 N O

COO- COO- +H 3 NC

H

CH 2

C

H 2 N O

CH 2

COO-

+H 3 NC

H

CH 2

OH

COO- +H 3 NC

H

CH

HO CH 3

COO- +H 3 NC

H

CH 2

SH

COO-