Equilibrium perturbation by isotope substitution.

Biochemistry
M I SchimerlikW W Cleland

Abstract

When malic enzyme is added to a mixture of malate-2-d, TPN, CO2, pyruvate, and TPNH at concentrations calculated to be at equilibrium, the TPNH level first drops and then increases slowly to its original level. This equilibrium perturbation is caused by slower cleavage of C-D than C-H bonds during hydride transfer as malate-2-d and TPNH are partly converted into TPND and malate-2-h in the process of establishing isotopic equilibrium. With malate-2-d, isotope effects for malic enzyme at pH 7.1 and malate dehydrogenase at pH 9.3 of 1.45 and 1.70-2.16 (depending on oxaloacetate level) were determined with this method, while the corresponding isotope effects on V/Kmalate and V for the chemical reactions were 1.5-1.8 and 1.0, and 1.9 and 1.5 for the two enzymes. The advantage of this method is its extreme sensitivity, and the lack of interference from various artifacts. The sensitivity is sufficient to permit determination of 13C and 15N isotope effects in favorable cases, and values of 1.031 for malic enzyme with 13CO2, and 1.047 for glutamate dehydrogenase with 15NH4+ have been determined. In the course of this work it was discovered that the equilibrium constants for oxidation by DPN, and oxidative decarboxylation by TPN are lowe...Continue Reading

Citations

Feb 9, 1977·Biochimica Et Biophysica Acta·H P MelocheW W Cleland
Mar 16, 1987·European Journal of Biochemistry·R E HäuslerE Latzko
Nov 22, 2001·Archives of Biochemistry and Biophysics·M A RishavyW W Cleland
Jul 8, 2014·Bioorganic Chemistry·Andrew S MurkinSvetlana A Kholodar
Apr 27, 2010·Nature Chemical Biology·Jefferson ChanAndrew J Bennet
Nov 23, 2013·Biochemistry·Christine E QuartararoJohn S Blanchard
Dec 7, 2013·Biochemistry·Debra Dunaway-MarianoFrank M Raushel
Jan 1, 1982·CRC Critical Reviews in Biochemistry·W W Cleland
Sep 7, 2006·Rapid Communications in Mass Spectrometry : RCM·Klaus J PetzkeCornelia C Metges
Jan 21, 1987·Journal of Theoretical Biology·W J Albery, J R Knowles
Dec 8, 2004·Archives of Biochemistry and Biophysics·W W Cleland
Feb 27, 2015·The British Journal of Nutrition·G Cantalapiedra-HijarH Fouillet
Nov 14, 2012·Current Opinion in Chemical Biology·Andrew J Bennet
Feb 22, 1977·Biochemistry·M I Schimerlik, W W Cleland
Feb 22, 1977·Biochemistry·M I Schimerlik, W W Cleland
Mar 22, 1977·Biochemistry·M H O'Leary, J A Limburg
Sep 16, 1980·Biochemistry·J S Blanchard, W W Cleland
May 27, 1980·Biochemistry·J E Rife, W W Cleland
May 16, 1989·Biochemistry·B J Bahnson, V E Anderson
Jul 29, 2010·Protein Science : a Publication of the Protein Society·Sarah A WackerEllis Bell
Oct 30, 2003·The Journal of Biological Chemistry·W Wallace Cleland
Aug 26, 1986·Biochemistry·S C Kim, F M Raushel
Aug 19, 2007·Journal of the American Chemical Society·M Ashley Spies, Michael D Toney

❮ Previous
Next ❯

Related Concepts

Trending Feeds

COVID-19

Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Blastomycosis

Blastomycosis fungal infections spread through inhaling Blastomyces dermatitidis spores. Discover the latest research on blastomycosis fungal infections here.

Nuclear Pore Complex in ALS/FTD

Alterations in nucleocytoplasmic transport, controlled by the nuclear pore complex, may be involved in the pathomechanism underlying multiple neurodegenerative diseases including Amyotrophic Lateral Sclerosis and Frontotemporal Dementia. Here is the latest research on the nuclear pore complex in ALS and FTD.

Applications of Molecular Barcoding

The concept of molecular barcoding is that each original DNA or RNA molecule is attached to a unique sequence barcode. Sequence reads having different barcodes represent different original molecules, while sequence reads having the same barcode are results of PCR duplication from one original molecule. Discover the latest research on molecular barcoding here.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Evolution of Pluripotency

Pluripotency refers to the ability of a cell to develop into three primary germ cell layers of the embryo. This feed focuses on the mechanisms that underlie the evolution of pluripotency. Here is the latest research.

Position Effect Variegation

Position Effect Variagation occurs when a gene is inactivated due to its positioning near heterochromatic regions within a chromosome. Discover the latest research on Position Effect Variagation here.

STING Receptor Agonists

Stimulator of IFN genes (STING) are a group of transmembrane proteins that are involved in the induction of type I interferon that is important in the innate immune response. The stimulation of STING has been an active area of research in the treatment of cancer and infectious diseases. Here is the latest research on STING receptor agonists.

Microbicide

Microbicides are products that can be applied to vaginal or rectal mucosal surfaces with the goal of preventing, or at least significantly reducing, the transmission of sexually transmitted infections. Here is the latest research on microbicides.