A phytase (EC 3.1.3.8) was extracted from rat intestinal bacterium, Klebsiella Sp. No. PG.-2, and purified 50-fold by ammonium sulphate fractionation, ion-exchange chromatography and gel filtration. The enzyme is inducible in nature. The pH optimum was at 6.0 for all the inositol phosphates studied and this characterized the enzyme as an acid phosphohydrolase. Of a range of potential substrates tested, only p-nitrophenyl phosphate alongwith the inositol phosphates was hydrolyzed. It exhibits a Km of 2.0 mM; temperature optimum of 37 degrees C and energy of activation 9,120 cal/mole for all the inositol phosphates studied. The activity was inhibited by Ag2+, Hg2+, Cu2+, fluoride and high substrate concentration.
Download full-text PDF |
Source |
---|
Plants (Basel)
December 2024
Institut für Angewandte Wissenschaft, Ausbau 5, 18258 Rukieten, Germany.
Phosphate (P) is the plant macronutrient with, by far, the lowest solubility in soil. In soils with low P availability, the soil solution concentrations are low, often below 2 [µmol P/L]. Under these conditions, the diffusive P flux, the dominant P transport mechanism to plant roots, is severely restricted.
View Article and Find Full Text PDFAsian J Endosc Surg
January 2025
Department of Obstetrics and Gynecology, Kyushu University Hospital, Fukuoka, Fukuoka, Japan.
Introduction: This study examined factors that affected sentinel lymph node (SLN) identification of patients with endometrial cancer having a preoperative estimation of low recurrent risk.
Methods: This study included 97 patients with endometrial cancer who attempted to identify SLN using a uterine cervical injection of technetium-99 m phytate under laparoscopic or robotic-assisted surgery at our institute. A preoperative single photon emission computed tomography (SPECT) and intraoperative gamma probe were used to detect hot nodes.
Metallomics
January 2025
Department of Environmental and Physical Sciences, Faculty of Science, Concordia University of Edmonton, Edmonton, Alberta, Canada.
Non-enzymatic glycation is the chemical reaction between the amine group of an amino acid and the carbonyl group of a reducing sugar. The final products of this reaction, advanced glycation end-products (AGEs), are known to play a key role in aging and many chronic diseases. The kinetics of the AGE formation reaction depends on several factors, including pH, temperature, and the presence of prooxidant metals, such as iron and copper.
View Article and Find Full Text PDFJ Agric Food Chem
January 2025
Qualisud, Université Montpellier, CIRAD, Montpellier SupAgro, Université d'Avignon, Université de La Réunion, Montpellier 34093, France.
Phytate in plants (inositol phosphates, InsPs) affects mineral bioavailability. However, methods for their quantification may lead to variable results, and some are nonspecific (spectrophotometric techniques). In this study, ion-pair high-performance liquid chromatography (HPLC) was coupled with post-column derivatization to allow fluorescence detection (FLD, λ324/λ364 nm) of InsPs.
View Article and Find Full Text PDFJ Biol Chem
December 2024
Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN, 37232; Department of Medicine, Division of Diabetes, Endocrinology and Metabolism, Vanderbilt University Medical Center, Nashville, TN, 37232. Electronic address:
Mechanistic Target of Rapamycin (mTOR) binds the small metabolite inositol hexakisphosphate (IP) as shown in structures of mTOR, however it remains unclear if IP, or any other inositol phosphate species, function as an integral structural element(s) or catalytic regulator(s) of mTOR. Here, we show that multiple, exogenously added inositol phosphate species can enhance the ability of mTOR and mTORC1 to phosphorylate itself and peptide substrates in in vitro kinase reactions, with the higher order phosphorylated species being more potent (IP=IP>IP>>IP). IP increased the V and decreased the apparent K of mTOR for ATP.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!