Two intracellular pools of soluble polyphosphate were identified by in vivo 31P NMR spectroscopy in the cyanobacterium Synechocystis sp. strain PCC 6308. Polyphosphate was present in the cells after growth in sulfur-limited media containing excess phosphate. The presence of polyphosphate was confirmed by transmission electron microscopy and chemical analysis. 31P NMR spectroscopy of whole cells treated with EDTA revealed two pools of mobile polyphosphate. A downfield shift and narrowing of part of the broad polyphosphate resonance was observed after EDTA treatment, suggesting that EDTA binds metal ions normally associated with some of the polyphosphate. Phosphate, but not polyphosphate, leaked out of the cells after this treatment. Addition of magnesium ions caused the downfield shift in the polyphosphate resonance to move back toward its original value. These data show that only part of the cation-complexed polyphosphate is accessible to the added EDTA and suggest that there are two internal fractions of NMR-visible polyphosphate in the cells, only one of which loses its associated cations to EDTA. Spheroplast formation showed that polyphosphate was not present in the periplasm of the cells.
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http://dx.doi.org/10.1007/s002030050560 | DOI Listing |
Biochim Biophys Acta Biomembr
January 2025
Department of Molecular Pathobiology, New York University, New York, NY, USA. Electronic address:
Inorganic polyphosphate (polyP) is a polymer that consists of a series of orthophosphates connected by high-energy phosphoanhydride bonds, like those found in ATP. In mammalian mitochondria, polyP has been linked to the activation of the mitochondrial permeability transition pore (mPTP). However, the details of this process are not completely understood.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
Department of Petroleum and Gas Engineering Technology, Federal Polytechnic of Oil and Gas, Bonny-island, PMB 5027, Rivers State, Nigeria.
Chromium-based lignosulfonate (CrLS) deflocculants that are commonly used in water-based drilling muds (WBDMs) to deflocculate bentonites under high temperature (HT), high-pressure (HP), and high-salinity (HS) oil well drilling conditions have been found to contain heavy metals such as chromium, which is toxic and degrades rapidly. However, different ways of addressing this issue have been proffered, including the use of natural polymers such as starch, cellulose, or anionic inorganic agents such as sodium polyphosphates with little or no impact. Other lignosulfonate (LS)-based deflocculants, like sodium-based LS and bio-based LS, have shown a number of benefits, such as being better for the environment, more soluble and evenly distributed in WBDMs, more resistant to salt contamination, easily biodegradable, safe, and able to go through different chemical changes.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
College of Chemistry Engineering and Materials Science, Tianjin University of Science and Technology, Tianjin 300457, China.
The durability and flame retardancy of cotton fabrics have been the focus of long-term research. In this paper, a method for preparing flame retardants through the direct modification of biomass was proposed, and the durable flame retardant of homologous cottonseed meal modified biomass flame retardants for cotton fabrics was achieved through biomass composition analysis and modeling. In this study, a cottonseed meal-phosphoric acid-boric acid synergistic bio-based flame retardant (CPB) was synthesized and characterized.
View Article and Find Full Text PDFWater Res
January 2025
National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China. Electronic address:
Hydroxylamine (HA) dosing is an effective strategy for promoting partial nitrification (PN); however, its impact on endogenous denitrification remains underexplored. In this study, long-term continuous HA dosing (1.4 mg/L) was introduced for over 110 days in a pilot-scale anaerobic/aerobic/anoxic (AOA) system treating municipal wastewater (66.
View Article and Find Full Text PDFInt J Biol Sci
January 2025
Department of Basic & Translational Sciences, School of Dental Medicine, University of Pennsylvania, USA.
Inositol polyphosphate-5-phosphatase E (INPP5E) is a 5-phosphatase critically involved in diverse physiological processes, including embryonic development, neurological function, immune regulation, hemopoietic cell dynamics, and macrophage proliferation, differentiation, and phagocytosis. Mutations in cause Joubert and Meckel-Gruber syndromes in humans; these are characterized by brain malformations, microphthalmia, situs inversus, skeletal abnormalities, and polydactyly. Recent studies have demonstrated the key role of INPP5E in governing intracellular processes like endocytosis, exocytosis, vesicular trafficking, and membrane dynamics.
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