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This article discusses the importance of effective waste management for environmental sustainability, public health, and global resource security. It highlights the development of green technologies in three areas: e-waste valorisation, extraction of bioactive compounds from food waste, and green technologies for microbial surface disinfection. The studies presented in the article demonstrate the advantages of these technologies in terms of time, cost, and energy efficiency compared to traditional methods. The article also emphasizes the need for optimization of operational parameters and the importance of research-based evidence to guide policy decisions. The authors suggest future actions for sustainability, including the development of a centralized database, funding for research and development, support for green start-ups, and the use of AI and machine learning algorithms for predictive modeling and process optimization. [Extracted from the article]

Phytochrome photoreceptors mediate light responses in plants and in many microorganisms. Here we report studies using ¹H-13C magic-angle spinning NMR spectroscopy of the sensor module of cyanobacterial phytochrome Cph1. Two isoforms of the red-light absorbing Pr ground state are identified. Conclusive evidence that photoisomerization occurs at the C15-methine bridge leading to a β-facial disposition of the ring D is presented. In the far-red-light absorbing Pfr state, strong hydrogen-bonding interactions of the D-ring carbonyl group to Tyr-263 and of N24 to Asp-207 hold the chromophore in a tensed conformation. Signaling is triggered when Asp-207 is released from its salt bridge to Arg-472, probably inducing conformational changes in the tongue region. A second signal route is initiated by partner swapping of the B-ring propionate between Arg-254 and Arg-222. [ABSTRACT FROM AUTHOR]

Crystallization of phytochromes and other photochromic proteins is hampered by the conformational changes that they undergo on exposure to light. As a canonical phytochrome, cyanobacterial Cph1 switches between two stable states upon absorption of red/far-red light. Consequently, it is mandatory to work in darkness from protein purification to crystal cryoprotection in order to ensure complete occupancy of one state or the other. With the simple and inexpensive methods that have been developed, phytochromes and other photochromic molecules can effectively be handled and crystallized, as has been demonstrated by the solution of the three-dimensional structure of the Cph1 sensory module. [ABSTRACT FROM AUTHOR]

Helicobacter pylori is a Gram-negative pathogenic microaerophile with a particular tropism for the mucosal surface of the gastric epithelium. Despite its obligatory microaerophilic character, it can metabolized-glucose and/ord-galactose in both oxidative and fermentative pathways via a Na+-dependent secondary active transport, a glucokinase and enzymes of the pentose phosphate pathway. We have assigned the Na+-dependent transport of glucose to the protein product of the H. pylori 1174 gene. The gene was heterologously expressed in a glucose transport-deficient Escherichia coli strain, where transport activities of radiolabelledd-glucose,d-galactose and 2-deoxy-d-glucose were restored, consistent with the expected specificity of the hexose uptake system in H. pylori.d-Mannose was also identified as a substrate. The HP1174 transport protein was purified and reconstituted into proteoliposomes, where sodium dependence of sugar transport activity was demonstrated. Additionally the tryptophan/tyrosine fluorescence of the purified protein showed quenching by 2-deoxy-d-glucose,d-mannose,d-glucose ord-galactose in the presence of sodium ions. This is the first reported purification and characterization of an active glucose transport protein member of the TC 2.1.7 subgroup of the Major Facilitator Superfamily, constituting the route for entry of sugar nutrients into H. pylori. A model is derived of its three-dimensional structure as a paradigm of the family. [ABSTRACT FROM AUTHOR]

Solid-state nuclear magnetic resonance (SSNMR) spectroscopy is used for the first time to examine the relative substrate-binding affinities of mutant forms of the Escherichia coli sugar transporter GalP in membrane preparations. The SSNMR method of 13C cross-polarization magic-angle spinning (CP-MAS) is applied to five site-specific mutants (W56F, W239F, R316W, T336Y and W434F), which have a range of different sugar-transport activities compared to the wild-type protein. It is shown that binding of the substrate D-glucose can be detected independently of sugar transport activity using SSNMR, and that the NMR peak intensities for uniformly 13C-labelled glucose are consistent with wild-type GalP and the mutants having different affinities for the substrate. The W239F and W434F mutants showed binding affinities similar to that of the wild-type protein, whereas the affinity of glucose-binding to the W56F mutant was reduced. The R316W mutant showed no detectable binding; this position corresponds to the second basic residue in the highly conserved (R/K)XGR(R/K) motif in the major facilitator superfamily of transport proteins and to a mutation in human GLUT1 found in individuals with GLUT1-deficiency syndrome. The T336Y mutant also showed no detectable binding; this mutation is likely to have perturbed helix structure or packing to an extent that conformational changes in the protein are hindered. The effects of the mutations on substrate-binding are discussed with reference to the putative positions of the residues in a 3D homology model of GalP based on the X-ray crystal structure of the E. coli glycerol-3-phosphate transporter GlpT. [ABSTRACT FROM AUTHOR]

The red/far-red-sensing biological photoreceptor phytochrome is a paradigmatic two-state signaling system. The two thermally stable states are interconverted via a photoreaction of the covalently bound tetrapyrrole chromophore. Applying recently developed solid-state nuclear magnetic resonance, we study both the chromophore and its protein pocket in the Pr (red-absorbing) and Pfr (far-red-absorbing) states. The observations show that the phototransformation combines local chemical reactions with a mesoscopic transition of order. Both the chromophore and its binding pocket are quasi-liquid and disordered in Pr, yet quasi-solid and ordered in Pfr. Possible biochemical implications are discussed. [ABSTRACT FROM AUTHOR]