Isotope trapping and kinetic isotope effect studies of rat liver alpha-(2-->6)-sialyltransferase

Biochemistry
M Bruner, B A Horenstein

Abstract

A mechanistic study of rat liver alpha-(2-->6) sialyltransferase (ST) is presented that includes isotope trapping experiments and kinetic isotope effects on V/K for the ST-catalyzed reaction of isotopically labeled CMP-N-acetylneuraminate and N-acetyllactosamine. The isotope trapping experiments confirmed that the kinetic mechanism is steady-state random, and further analysis indicated that for this sialyltransferase the experimentally observed isotope trapping ratio (product trapped/substrate released) was equivalent to the commitment to catalysis, Cf, the quantity required to correct the kinetic isotope effects. Cf was found to range from 1.0 (at 1.6 mM LacNAc) to 1.7 (at 100 mM LacNAc). After correction for Cf, the isotope effects were as follows: secondary beta-dideuterium, 1.04-1. 05; anomeric carbon primary 14C, 1.000 +/- 0.004; a small 3H binding effect of 1.016 +/- 0.007 at C9; and a carboxylate carbon secondary 14C isotope effect of 0.998 +/- 0.004. This pattern of KIEs is quite different than observed for solvolysis of CMP-NeuAc [Horenstein, B. A., and Bruner, M. (1996) J. Am. Chem. Soc. 118, 10371-10379]. Based on the results of ab-initio modeling of isotope effects, a hypothesis is presented which reconciles the unu...Continue Reading

Citations

Nov 9, 2002·Medicinal Research Reviews·Xiaofang WangXin-Shan Ye
Oct 2, 2001·Current Opinion in Chemical Biology·V L Schramm
Jul 16, 2013·Chemical Reviews·Katarzyna Swiderek, Piotr Paneth
Aug 9, 2011·Nature Chemical Biology·Seung Seo LeeBenjamin G Davis
Sep 26, 2015·Journal of Medicinal Chemistry·Wenming LiXin-Shan Ye
Sep 23, 2006·Carbohydrate Research·Bini Mathew, Richard R Schmidt
Sep 21, 2016·Biochemistry·Yojiro HamadaMasanori Tachikawa
Sep 30, 2016·Medicinal Research Reviews·Rémi Szabo, Danielle Skropeta
Feb 7, 2017·Journal of Medicinal Chemistry·Jian GuoXin-Shan Ye
Oct 22, 2005·The Journal of Organic Chemistry·Masayuki IzumiHironobu Hashimoto

❮ 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.