On-line characterization of peroxidation intermediates of NAD{sup +} by CE-ESI-MS
- Pacific Northwest Lab., Richland, WA (United States)
Equine liver alcohol dehydrogenase (LADH) is one of the NAD-dependent enzymes with various physiological functions. LADH also exhibits several alternative catalytic activities. Among them, the most unusual one is the LADH-catalyzed degradation of NAD+ in the presence of hydrogen peroxide. A two-step reaction mechanism has been proposed for this enzymatic peroxidation. In the first (fast) step, NAD+ catalyzed by LADH is converted to a (so far) unidentified intermediate: {open_quotes}compound I{close_quotes}. The following slower step is enzyme independent and consists of at least two distinct processes; one of them leads to another unknown substance: {open_quotes}compound Y{close_quotes} which is the product of further reaction of {open_quotes}compound I{close_quotes} with excess H{sub 2}O{sub 2}; another process converts {open_quotes}compound I{close_quotes} to adenosine(5{prime})- diphospho(5)-{Beta}-D-ribose-NHCH=C(CHO)CONH{sub 2} (NADX) if catalase is added to destroy excess H{sub 2}O{sub 2} soon after the end of the faster enzymatic step. One of the advantages of capillary electrophoresis (CE) is its fast operation cycle, which could be utilized to monitor relatively slow reaction processes. Capillary electrophoresis-mass spectrometry (CE-MS) has the capability of high resolution separations coupled with highly sensitive and selective detection providing crucial molecular weight and structural information.
- OSTI ID:
- 210625
- Report Number(s):
- CONF-9505261-; TRN: 96:001157-0064
- Resource Relation:
- Conference: 43. American Society of Mass Spectrometry (ASMS) conference on mass spectrometry and allied topics, Atlanta, GA (United States), 21-26 May 1995; Other Information: PBD: 1995; Related Information: Is Part Of Proceedings of the 43rd ASMS conference on mass spectrometry and allied topics; PB: 1411 p.
- Country of Publication:
- United States
- Language:
- English
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