Biochem-20 amino acid-Sulfur-containing R groups

3 letter code: Methionine

Met

3 letter code: Cysteine

Cys

1 letter code: Methionine

M

1 letter code: Cysteine

C

Methionine

Cysteine

pK1, (-COOH): Methionine

2.28

pK1, (-COOH): Cysteine

1.96

pK2 (-NH3+): Methionine

9.21

pK2 (-NH3+): Cysteine

10.28

pKr (R group):Methionine

n/a

pKr (R group):Cysteine

8.3