Enzyme Catalysis of 1, 2-Amino Shifts: The Cooperative Action of B6, B12, and Aminomutases (CROSBI ID 263838)
Prilog u časopisu | izvorni znanstveni rad | međunarodna recenzija
Podaci o odgovornosti
Wetmore, Stacey D. ; Smith, David M. ; Radom, Leo
engleski
Enzyme Catalysis of 1, 2-Amino Shifts: The Cooperative Action of B6, B12, and Aminomutases
Ab initio molecular orbital theory is used to investigate 1, 2-amino shifts catalyzed by aminomutases, coenzyme B12, and vitamin B6 (in the form of pyridoxal 5‘-phosphate or PLP). Our calculations suggest essential catalytic roles for each of B12, B6, and the enzyme in aminomutase-catalyzed reactions. In the first place, coenzyme B12 provides a source of abstracting radicals, allowing the rearrangement reaction to take place on the radical surface. The involvement of radicals is supported by comparison of experimental and theoretical electron paramagnetic resonance parameters. Next, B6 allows the enzyme to lower the barrier height by introducing a double bond (allowing a low-energy intramolecular rearrangement pathway) and by providing a suitable site for partial protonation (preventing overstabilization of the reaction intermediate which could lead to enzyme inactivation). The PLP hydroxyl group is also identified as an important participant in these reactions. Finally, the enzyme holds the various reaction components in place and is the source of acidic functional groups that can provide partial protonation.
Enzyme Catalysis ; Vitamin B6 ; Vitamin B12 ; Aminomutases
nije evidentirano
nije evidentirano
nije evidentirano
nije evidentirano
nije evidentirano
nije evidentirano
Podaci o izdanju
123 (36)
2001.
8678-8689
objavljeno
0002-7863
10.1021/ja010211j