PMID: 16663104Jul 1, 1983

Purification and Properties of Flavonol-Ring B Glucosyltransferase from Chrysosplenium americanum

Plant Physiology
K L BajajR K Ibrahim

Abstract

A novel glucosyltransferase which catalyzed the transfer of glucose from UDP-glucose to positions 2' and 5' of partially methylated flavonols was isolated from the shoots of Chrysosplenium americanum Schwein ex Hooker. It was purified 225-fold by ammonium sulfate precipitation and successive chromatography on Sephadex G-100, hydroxyapatite, and polybuffer ion exchanger. This glucosyltransferase appeared to be a single polypeptide with an apparent molecular weight of 42,000 daltons, pH optimum of 7.5 to 8.0, and an isoelectric point of 5.1. It had low but similar K(m) values for the 2' and 5' positions of flavonol substrates and the cosubstrate UDP-glucose and was inhibited by both reaction products, the glucosides formed, and UDP.Glucosyltransferase activity was independent of divalent cations, was not inhibited by EDTA, but showed requirement for SH groups. The differential effect on enzyme activity of metal ions, especially cupric ion, and various SH group reagents seemed to indicate the involvement of two active sites in the glucosylation reaction; the site specific for 2' activity being more susceptible than that of the 5' activity. The substrate specificity expressed by this glucosyltransferase and the requirement of at le...Continue Reading

Citations

Nov 1, 1992·Plant Physiology·N YalpaniM Schulz
Aug 1, 1984·European Journal of Biochemistry·H Khouri, R K Ibrahim
Sep 1, 1991·Archives of Biochemistry and Biophysics·L Latchinian-Sadek, R K Ibrahim

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.

Synthetic Genetic Array Analysis

Synthetic genetic arrays allow the systematic examination of genetic interactions. Here is the latest research focusing on synthetic genetic arrays and their analyses.

Congenital Hyperinsulinism

Congenital hyperinsulinism is caused by genetic mutations resulting in excess insulin secretion from beta cells of the pancreas. Here is the latest research.

Neural Activity: Imaging

Imaging of neural activity in vivo has developed rapidly recently with the advancement of fluorescence microscopy, including new applications using miniaturized microscopes (miniscopes). This feed follows the progress in this growing field.

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.

Epigenetic Memory

Epigenetic memory refers to the heritable genetic changes that are not explained by the DNA sequence. Find the latest research on epigenetic memory here.

Cell Atlas of the Human Eye

Constructing a cell atlas of the human eye will require transcriptomic and histologic analysis over the lifespan. This understanding will aid in the study of development and disease. Find the latest research pertaining to the Cell Atlas of the Human Eye here.

Femoral Neoplasms

Femoral Neoplasms are bone tumors that arise in the femur. Discover the latest research on femoral neoplasms 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.