REACTIVE OXYGEN SPECIES - Oxidation of Amino Acids, Peptides, and Proteins: Kinetics and Mechanism - page 171

TABLE 4.13. Kinetic Isotope Effects for Attacks of Hydroxyl Radical on Gly
Anion. Estimated Uncertainty ±20%

Attack at the Methylene-c

k H / k D k H / k D

gly Anions Solvent Overall glycyl

Primary effects
NH 2 -cH 2 -cOO − /NH 2 -
cD 2 -cOO −

H 2 O/D 2 O 1.3 1.6

ND 2 -cH 2 -cOO − /ND 2 -
cD 2 -cOO −

D 2 O/D 2 O 1.3 2.0

Secondary effects
NH 2 -cH 2 -cOO − /ND 2 -
cH 2 -cOO −

H 2 O/D 2 O 1.3 1.3

NH 2 -cD 2 -cOO − /ND 2 -
cD 2 -cOO −

H 2 O/D 2 O 1.3 1.7

Primary + secondary effects
NH 2 -cH 2 -cOO − /NH 2 -
cD 2 -cOO −

H 2 O/D 2 O 1.8 2.6

ND 2 -cH 2 -cOO − /ND 2 -
cD 2 -cOO −

D 2 O/H 2 O 1.0 1.2

Attack at the N-site

k H / k D k H / k D k H / k D

N-Attack Aminomethyl Aminyl

Primary effects
NH 2 -cH 2 -cOO − /ND 2 -
cH 2 -cOO −

H 2 O/D 2 O 1.3 1.2 1.5

ND 2 -cD 2 -cOO − /ND 2 -
cD 2 -cOO −

D 2 O/D 2 O 1.3 1.3 1.2

Secondary effects
NH 2 -cH 2 -cOO − /ND 2 -
cD 2 -cOO −

H 2 O/D 2 O 1.2 1.1 1.3

ND 2 -cH 2 -cOO − /ND 2 -
cD 2 -cOO −

H 2 O/D 2 O 1.2 1.3 1.0

Primary + secondary effects
NH 2 -cH 2 -cOO − /ND 2 -
cD 2 -cOO −

H 2 O/D 2 O 1.5 1.5 1.5

NH 2 -cD 2 -cOO − /ND 2 -
cH 2 -cOO −

D 2 O/H 2 O 1.1 1.0 1.1

Data are taken from Štefanić et al. [294].