Conjugate Base Research Articles

Biomolecular investigations into BBI reveal an enzymatic mechanism for PUFA isomerisation in bifidobacterium CFA bioconversion strains

Multiple species of Bifidobacterium exhibit the ability to bioconvert conjugated fatty acids (CFAs), which is considered an important pathway for these strains to promote host health. However, there has been limited progress in understanding the enzymatic mechanism of CFA bioconversion by bifidobacteria, despite the increasing number of studies identifying CFA-producing strains. The protein responsible for polyunsaturated fatty acid (PUFA) isomerization in B. breve CCFM683 has recently been discovered and named BBI, providing a starting point for exploring Bifidobacterium isomerases (BIs). This study presents the sequence classification of membrane-bound isomerases from four common Bifidobacterium species that produce CFA. Heterologous expression, purification, and enzymatic studies of the typical sequences revealed that all possess a single c9, t11 isomer as the product and share common features in terms of enzymatic properties and catalytic kinetics. Using molecular docking and alanine scanning, Lys84, Tyr198, Asn202, and Leu245 located in the binding pocket were identified as critical to the catalytic activity, a finding further confirmed by site-directed mutagenesis-based screening assays. Overall, these findings provide insightful knowledge concerning the molecular mechanisms of BIs. This will open up additional opportunities for the use of bifidobacteria and CFAs in probiotic foods and precision nutrition.

The influence of catalyst structure on acidic strength of –SO3H groups for alkyl levulinate synthesis from biomass–derived feedstocks using sulfonic acid functionalized flexible MOF catalyst

A Brönsted acidic BUT−8(Cr)–SO3H metal–organic framework was used for the synthesis of ethyl levulinate from two different biomass–derived platform chemicals viz. furfuryl alcohol and levulinic acid. The catalyst was well characterized using various methods such as PXRD, FTIR spectroscopy, acid–base titration, NH3–TPD, TGA–DTA, SEM, TEM as well as the computational density functional theory (DFT) method. The performance of BUT–8(Cr)–SO3H catalysts was found to be superior to other catalysts (HZSM–5, H–Beta, and amberlyst –15) taken in this study. The sulfonic acid moieties bound to the aromatic naphthalene structure of BUT–8(Cr)–SO3H MOF were found to have a much stronger influence on the catalytic performance than the sulfonic acid moieties bound to the styrene framework of amberlyst–15. The key discoveries regarding the Brönsted acidic characteristics were computed via DFT incorporating the hydrogen removal energy, molecular electrostatic potential maps, and stability of the conjugate base of –SO3H moieties. The trend in the DFT–derived values was in the following order: BUT–8(Cr)–SO3H > Linker–naph –SO3H > Amberlyst–15. The results also indicate the influence of Cr metal on MOF structure to increase the acidic strength of the –SO3H group. The reaction optimization using DOE, recyclability, leaching study, and substrate scope study for both pathways using BUT–8(Cr)–SO3H were obtained.

Influence of activated protons and acid–base pairs on proton conduction in imino-functionalized MOF-based hybrid membranes

The rich activated protons and effective proton-conducting paths are of importance to improve conductivities of conductors. Herein, a series of Brönsted acids as proton carrier and proton transfer sites is introduced into the highly stable MOF, contributing to create plentiful hydrogen bonds within frameworks. Consequently, the trifluoromethanesulfonic acid-embedded JUC-1000 ([Cu24(BDPO)12(H2O)12]) displays the relatively highest conductivity of 7.04 × 10−4 S cm−1 under ∼98% RH and 328 K, ∼16 times that of JUC-1000 (4.47 × 10−5 S cm−1). When TMSA@JUC-1000 (TMSA = CF3SO3H) blended with chitosan (CS), the proton conductivity of TMSA@JUC-1000/CS-15 is the highest at ∼76% RH and 328 K (1.01×10−2 S cm−1), which is six times higher than that of JUC-1000/CS (1.85×10−3 S cm−1). The CS contains abundant –NH2 and –OH groups as proton jumping sites, which would activate the –NH– or –OH bonds of JUC-1000 and the acidic groups in Brönsted acids. These would result in an increased content of activated protons and effective formation of H-bonding nets by acid-base interactions. The findings provide valuable insights into the potential application of MOFs materials in energy devices.

Zirconium induced surfaces frustrated Lewis acid-base pairs for BiOBr boosting CO2 photoreduction

Conversion of CO2 to carbon-based fuels via photocatalytic reduction, as a prospective approach, could alleviate energy shortages and environmental problems. However, the adsorption and activation of CO2 in the process of photocatalytic CO2 reduction are still great challenge. Herein, Zr isomorphous substituted BiOBr catalyst with surface frustrated Lewis acid-base pairs (SFLPs) are formed by a convenient chemical method. The photocatalytic activity of CO2 reduction for optimal Zr-BiOBr is significantly improved, with CO yield of 185.7 μmol·g−1·h−1 and CH4 of 0.7 μmol·g−1·h−1, being 9.2 - fold and 3.2 - fold higher than that of original BiOBr, respectively. It is found that zirconium is considered as Lewis acid site and lattice oxygen as Lewis base site, which could effectively boost the adsorption and activiation of CO2 molecules. This work not only demonstrates that construction of SFLPs for catalyst could be taken as an effective tactics for CO2 adsorption and activation, but also suggests a possible photocatalytic mechanism in depth.

Efficient nitrite-to-ammonia electroreduction over Zr-Ni frustrated Lewis acid-base pairs

Efficient nitrite-to-ammonia electroreduction over Zr-Ni frustrated Lewis acid-base pairs

Synthesis of MD‐1‐2 co‐sensitizers for 10.35% efficient acid–base pairing with N3 in DSSCs

This work presents a comprehensive investigation of novel organic dyes MD‐1‐2 as active acid and base co‐sensitizers in dye‐sensitized solar cells (DSSCs), using well‐known Ru(II)‐based N3 dyes. These co‐sensitizers contain a triphenylamine ring as a donor scaffold linked with an electron‐withdrawing cyanopyridyl and cyano benzoic acid acceptor for MD‐1‐2. In this study, we demonstrated the significant impact of base dyes with pyridine anchoring units on the photovoltaic parameters of N3‐sensitized devices. This methodology takes advantage of the ability of carboxyl and pyridyl moieties to interact with the Brønsted acid and Lewis acid sites on TiO2 surfaces, respectively. By reducing competition between dyes for surface binding, dye packing density on the TiO2 is enhanced while electron recombination is minimized, leading to higher photovoltage. Furthermore, the influence of varying sensitizer/co‐sensitizer ratios was comprehensively studied. Outcomes showed devices made using co‐sensitizer MD‐1‐2 with sensitizer N3 at all relative concentrations surpassed those with only N3. Importantly, the co‐sensitized devices that were made utilizing 0.3 mM acid–base MD‐1 and N3 sensitizer had the greatest solar energy capacity. It had a power conversion efficiency of 10.35%, a short‐circuit current density of 20.01 mA·cm−2, and an open‐circuit voltage of 752 mV. The results provide fresh insight into optimizing devices to create DSSCs with improved efficiency by choosing acceptable co‐sensitizers at suitable concentrations.

A DFT study on the formation mechanism of side product 1,2-propanediol in the hydrogenation of dimethyl oxalate over copper catalyst

The costly separation of 1,2-propanediol (1,2-PDO), an unavoidable byproduct in the hydrogenation of dimethyl oxalate (DMO), significantly hampers the economic viability of coal-to-ethylene glycol (EG) technology. To address this challenge, the formation mechanism of the side product 1,2-PDO on the Cu(111) and Cu2O(111) surfaces during DMO hydrogenation was investigated, which focused on the active sites of copper catalyst and the dominant pathway through density functional theory calculation. The thermodynamics of each elementary step and the adsorption behavior of various species involved in the reaction network along with the local density of states and charge density difference were systematically analyzed. The results indicate that 1,2-PDO is generated more favorably on the Cu2O(111) surface than that on the Cu(111) surface, owing to the Lewis acid-base pairs, i.e. Cu+ us and O– suf sites, present on the Cu2O(111) surface, which strengthens the binding of reactants, products, and reaction intermediates to the substrate. EG reacts primarily with methanol (MeOH) to form 1,2-PDO through Guerbet alcohol condensation reaction through three consecutive steps: alcohol dehydrogenation, aldol condensation, and unsaturated aldehyde hydrogenation. The O– suf sites promote the dehydrogenation of alcohols into aldehydes, the generation of enolates during aldol condensation and the hydrogenation of unsaturated aldehydes, while the Cu+ us sites are responsible for the C–C coupling reaction. These findings may shed light on the mechanism of 1,2-PDO formation over Cu catalyst and provide fundamental knowledge for the development of more efficient catalysts and process optimization.

Understanding the mechanism of propane dehydrogenation over coordinatively unsaturated Co-O acid-base pairs and the inhibition effect of trace oxygen

High temperature and a reducing atmosphere are characteristic of propane dehydrogenation (PDH) reaction. Under such condition, the real surface structure of catalysts often differs from that in the ambient environment, particularly for CoOx species with multiple valence states and coordination. Here, a combination of in situ/operando Raman spectroscopy, in situ UV–Vis diffuse reflectance spectroscopy (DRS), and density functional theory (DFT) calculations reveal that coordinatively unsaturated Co-O (Cocu-O) acid-base pairs via lattice oxygen consumption are the PDH active sites of CoOx/Al2O3 catalysts. This highly dispersed Cocu-O species exhibit a C3H6 formation rate and C3H6 selectivity as high as 2 mmol‧gcat−1‧min−1 and 95 %, respectively, which is comparable to most state-of-the-art CoOx-based catalysts. However, industrial C3H8 raw gases typically contain 10–1000 ppm oxygen gas, and the complete eliminating oxygen increases costs. PDH catalytic performance of CoOx/Al2O3 catalysts is sensitive to the extremely low concentration of oxygen gas and is significantly inhibited by it. The fundamental reason is that the concentration of Cocu active sites is determined by the competitive reaction between the filling of trace oxygen on oxygen vacancies and lattice oxygen consumption. The reaction rate of the former is significantly higher than that of the latter. The higher reducibility of CoOx species leads to relatively weaken inhibition of trace oxygen for PDH activity. The oxygen content in the propane feed gas is a non-negligible factor in the development of new Co-based PDH catalysts, especially for their industrial applications.

Zirconia-incorporated yttria with a Lewis pair of acid–base surface sites for chemoselective dehydration of alcohols into alpha olefins

Alpha olefins are currently made by ethylene oligomerization to a broad range of carbon number. An alternative conversion is selective alcohol dehydration in which the conventional catalyst development focused on the addition of any basic components into acidic supports. We herein demonstrated that the Zr4+ addition to Y2O3 (acid-to-base addition) was more effective than the Y3+ addition to ZrO2 in alcohol dehydration to alpha olefins. The zirconia-incorporated yttria with 4 mol% Zr (named 4ZIY) was structurally more stable than the yttria-stabilized zirconia (YSZ) counterpart. Moreover, the 4ZIY showed a high purity of alpha olefins when various C4 and C6 alcohols were used. Catalyst characterization works revealed that the 4ZIY contains a large amount of strong Lewis base sites, which is associated with oxygen vacancy, with a little Lewis acid sites. Consequently, the 4ZIY is suggested to have the favorable acid–base pair for the conversion of alcohols to alpha olefins.

A Chiral B-N Adduct as a New Frontier in Ferroelectrics and Piezoelectric Energy Harvesting.

Within the burgeoning field of electronic materials, B-N Lewis acid-base pairs, distinguished by their partial charge distribution across boron and nitrogen centers, represent an underexplored class with significant potential. These materials exhibit inherent dipoles and are excellent candidates for ferroelectricity. However, the challenge lies in achieving the optimal combination of hard-soft acid-base pairs to yield B-N adducts with stable dipoles. Herein, we present an enantiomeric pair of B-N adducts [R/SC6H5CH(CH3)NH2BF3] (R/SMBA-BF3) crystallizing in the polar monoclinic P21 space group. The ferroelectric measurements on RMBA-BF3 gave a rectangular P-E hysteresis loop with a remnant polarization of 7.65 μC cm-2, a value that aligns with the polarization derived from the extensive density-functional theory computations. The PFM studies on the drop-casted film of RMBA-BF3 further corroborate the existence of ferroelectric domains, displaying characteristic amplitude-bias butterfly and phase-bias hysteresis loops. The piezoelectric nature of the RMBA-BF3 was confirmed by its direct piezoelectric coefficient (d33) value of 3.5 pC N-1 for its pellet. The piezoelectric energy harvesting applications on the sandwich devices fabricated from the as-made crystals of RMBA-BF3 gave an open circuit voltage (VPP) of 6.2 V. This work thus underscores the untapped potential of B-N adducts in the field of piezoelectric energy harvesting.

Towards Two Bloch Sphere Representation of Pure Two-Qubit States and Unitaries.

We extend Bloch sphere formalism to pure two-qubit systems. Combining insights from Geometric Algebra and the analysis of entanglement in different conjugate bases we identify two Bloch sphere geometry that is suitable for representing maximally entangled states. It turns out that the relative direction of the coordinate axes of the two Bloch spheres may be used to describe the states. Moreover, the coordinate axes of one Bloch sphere should be rignt-handed and those of the other one should be left-handed. We describe and depict separable and maximally entangled states as well as entangling and non-entangling rotations. We also offer a graphical representation of the workings of a CNOT gate for different inputs. Finally, we provide a way to also represent partially entangled states and describe entanglement measures related to the surface area of the sphere enclosing the state representation.

Experimental and computational insights into the mechanism of destabilization of poly(acrylic acid)-capped silver nanoparticles induced by weak conjugate bases

Herein we report a systematic study of the effects of H2PO4− and ClO4− on the stability of poly(acrylic acid)-capped silver nanoparticles (PAA-AgNPs). Spectroscopic titration revealed that a smaller amount of ClO4− is required to detach PAA, and a blue-shift in surface plasmon resonance (SPR) was observed relative to H2PO4−, owing to its electron accepting nature which leads to a weaking of the PAA-AgNP donor bond. Experimental observations were supported by DFT calculations, which revealed that complexation of AgNPs with ionized PAA, H2PO4– and ClO4− is mediated by the electron affinity of the AgNP and the conjugated bases. Electron donation by the weak acids leads to the weakening of the PAA-AgNP donor bond, whereby ClO4− contributes more to the destabilization of the PAA capped AgNPs due to its greater electron affinity. Additionally, H2PO4− can form hydrogen bonds with PAA, which promotes the formation of aggregates. Moreover, DFT calculations have shown that the structure of the model Ag14 cluster is significantly distorted in the presence of H2PO4−, more so than in the case of ClO4−. The findings are supported by the experimental quantification of residual PAA by differential scanning calorimetry and solid-state total organic carbon analysis (SSM-TOC), and powder X-ray diffraction (XRD).

Cation-mediated acid-base pairs for mild oxidative cleavage of lignocellulosic β-1,4-glycosidic bonds

Solar-driven lignocellulosic biomass photoreforming holds significant promise for the production of value-added chemicals and fuels. The cleavage of the β-1,4-glycosidic bond is crucial for the effective conversion of lignocellulosic biomass. Polymeric carbon nitride (PCN) with acid-base pairs (M-C sites) is developed through heteroatomic carbon incorporation and cation insertion. It can be used for the gentle oxidation of cellobiose to monosaccharides, bypassing the formation of organic acids such as gluconic acid and glucaric acid. A series of different alkaline/alkaline-earth cation for regulation of acid-base pairs exhibited a negative correlation between β-1,4-glycosidic bond cleavage and cation radii. In particular, the introduction of short-radius cations (such as Li) into PCN enabled the formation of acid-base (M-C) pairs characterized by strong acidity. It also enhanced electron delocalization around M-C sites, potentially promoting the generation of reactive radicals in the reaction. Electron paramagnetic resonance analysis confirmed the presence of •OH radicals. The mild oxidative species, are the primary reactive radicals responsible for β-1,4-glycosidic bond cleavage in cellobiose. This study provides insightful evidence for the rational regulation of acid-base sites in facilitating β-1,4-glycosidic bond cleavage. It sheds light on the oxidative cleavage mechanisms integral to lignocellulosic biomass photoreforming, offering insights for advancing sustainable biomass conversion technologies.

Enhanced proton conductivity of sulfonated poly(ether ether ketone) membranes by constructing cation‐π through doping ammonium ionic liquid and graphene oxide

AbstractIn this paper, sulfonic acid functionalized benzothiazole ionic liquid ([(CH2)3SO3HBth] [H2PO4]) and graphene oxide were combined together through the cation‐π. The sulfonated poly (ether ether ketone) was doped with ionic liquid‐modified GO (IL‐GO) to prepare the SPEEK/IL‐GO composite membrane through the solution casting method. The SO3H and benzothiazole rings act as both proton acceptors and proton donors during proton transport and can replace the role of water in medium‐ and high‐temperature environments, increasing the proton transport sites to a certain extent and increasing the proton conductivity of the SPEEK/IL‐GO composite membrane. The proton conductivity of the SPEEK/IL‐GO‐2 composite membrane achieved an 18.02 mS/cm at 120°C, which is 2.43 times higher than that of the pristine SPEEK membrane. This paper provided a method for increasing proton conductivity and limiting IL loss of the SPEEK membrane.Highlights [(CH2)3SO3HBth][H2PO4] and graphene oxide were combined through cation‐π. The benzothiazole ring and SO3H form acid–base pairs. The proton conductivity of SPEEK/IL‐GO‐2 membrane achieved 18.02 mS/cm.

Vibrational signatures of dynamic excess proton storage between primary amine and carboxylic acid groups.

Ammonium and carboxylic moieties play a central role in proton-mediated processes of molecular recognition, charge transfer or chemical change in (bio)materials. Whereas both chemical groups constitute acid-base pairs in organic salt-bridge structures, they may as well host excess protons in acidic environments. The binding of excess protons often precedes proton transfer reactions and it is therefore of fundamental interest, though challenging from a quantum chemical perspective. As a benchmark for this process, we investigate proton storage in the amphoteric compound 5-aminovaleric acid (AV), within an intramolecular proton bond shared by its primary amine and carboxylic acid terminal groups. Infrared ion spectroscopy is combined with abinitio Molecular Dynamics (AIMD) calculations to expose and rationalize the spectral signatures of protonated AV and its deuterated isotopologues. The dynamic character of the proton bond confers a fluxional structure to the molecular framework, leading to wide-ranging bands in the vibrational spectrum. These features are reproduced with remarkable accuracy by AIMD computations, which serves to lay out microscopic insights into the excess proton binding scenario.

Spectroscopic Characterization of Thermal Methane Activation by Lewis-Acid-Base Pair in a Gas-Phase Metal Nitride Anion Ta2N3.

Activation and transformation of methane is one of the "holy grails" in catalysis. Understanding the nature of active sites and mechanistic details via spectroscopic characterization of the reactive sites and key intermediates is of great challenge but crucial for the development of novel strategies for methane transformation. Herein, by employing photoelectron velocity-map imaging (PEVMI) spectroscopy in conjunction with quantum chemistry calculations, the Lewis acid-base pair (LABP) of [Taδ+-Nδ-] unit in Ta2N3 - acting as an active center to accomplish the heterolytic cleavage of C-H bond in CH4 has been confirmed by direct characterization of the reactant ion Ta2N3 - and the CH4-adduct intermediate Ta2N3CH4 -. Two active vibrational modes for the reactant (Ta2N3 -) and four active vibrational modes for the intermediate (Ta2N3CH4 -) were observed from the vibrationally resolved PEVMI spectra, which unequivocally determined the structure of Ta2N3 - and Ta2N3CH4 -. Upon heating, the LABP intermediate (Ta2N3CH4 -) containing the NH and Ta-CH3 unit can undergo the processes of C-N coupling and dehydrogenation to form the product with an adsorbed HCN molecule.

Local In-O-Pd Lewis acid-base pair boosting CO2 selective hydrogenation to methanol

CO2 hydrogenation into valuable chemicals is industrially essential but very challenging since CO2 is chemically inert and the selectivity is difficult to control. Here, we design and construct In2O3 supported Pd single atoms (Pd1/In2O3 SAC) to boost the methanol yield (254.8 gmethanol·gPd−1·h−1) and selectivity (99.4 %) via the Lewis acid-base pair, which activates the CO2 and forms the intermediate species of formate (HCOO*). The comprehensive experimental and theoretical results confirm that the local Lewis acid-base pair is composed of the isolated Pd atom coupling with the adjacent O and In atoms. The space–time yield (STY) of methanol over Pd1/In2O3 SAC is around 1.7 times higher than the best reported catalysts under comparable conditions. The strategy of constructing local Lewis acid-base pairs with single-atom site and metal oxides reported in this work opens new avenues to develop highly selective catalysts for CO2 utilization.

Molecular and metabolic characterization of petroleum hydrocarbons degrading Bacillus cereus.

Hydrocarbon constituents of petroleum are persistent, bioaccumulated, and bio-magnified in living tissues, transported to longer distances, and exert hazardous effects on human health and the ecosystem. Bioaugmentation with microorganisms like bacteria is an emerging approach that can mitigate the toxins from environmental sources. The present study was initiated to target the petroleum-contaminated soil of gasoline stations situated in Lahore. Petroleum degrading bacteria were isolated by serial dilution method followed by growth analysis, biochemical and molecular characterization, removal efficiency estimation, metabolites extraction, and GC-MS of the metabolites. Molecular analysis identified the bacterium as Bacillus cereus, which exhibited maximum growth at 72 hours and removed 75% petroleum. Biochemical characterization via the Remel RapID™ ONE panel system showed positive results for arginine dehydrolase (ADH), ornithine decarboxylase (ODC), lysine decarboxylase (LDC), o-nitrophenyl-β-D-galactosidase (ONPG), p-nitrophenyl-β-D-glucosidase (βGLU), p-nitrophenyl-N-acetyl-β-D-glucosaminidase (NAG), malonate (MAL), adonitol fermentation (ADON), and tryptophane utilization (IND). GC-MS-based metabolic profiling identified alcohols (methyl alcohol, o-, p- and m-cresols, catechol, and 3-methyl catechol), aldehydes (methanone, acetaldehyde, and m-tolualdehyde), carboxylic acid (methanoic acid, cis,cis-muconic acid, cyclohexane carboxylic acid and benzoic acid), conjugate bases of carboxylic acids (benzoate, cis,cis-muconate, 4-hydroxybenzoate, and pyruvate) and cycloalkane (cyclohexene). It suggested the presence of methane, methylcyclohexane, toluene, xylene, and benzene degradation pathways in B. cereus.

MOFs-derived (Fe3O4/Fe2O3)OH@C-X in-situ form frustrated Lewis acid-base pairs for visible-light-driven photocatalytic CO2 reduction

Frustrated Lewis pairs (FLPs) have demonstrated their capacity to capture and react with CO2, presenting a novel method for CO2 reduction. Despite this, their practical application remains limited due to a complex preparation process, poor stability, and regeneration challenges. We address these issues in this study by pyrolyzing a metal-organic framework (MOF) to form in-situ FLPs on an iron oxide surface. The resulting (Fe3O4/Fe2O3)OH@C-400 composite exhibits a significantly improved CO2 reduction rate of 173.3 μmol g−1 h−1, which is approximately 13.4 times higher than that of Fe2O3 and 10.9 times higher than that of Fe3O4. Both theoretical and experimental findings confirm that the creation of heterostructured hollow spheres and in-situ FLPs enhances visible light absorption, improves the separation and transfer of photogenerated carriers, and increases the photocatalytic efficiency for CO2 reduction. The H/D kinetic isotope effect suggests that water plays a crucial role in the limiting step of CO2 photoreduction. In-situ FTIR results corroborate the formation of COOH* as a critical intermediate in photocatalytic CO2 reduction over (Fe3O4/Fe2O3)OH@C-X. This research provides a novel insight into catalyst material design and mechanism research for photocatalytic CO2 reduction.

Strengthening the basics: acids and bases influence vascular structure and function, tissue perfusion, blood pressure, and human cardiovascular disease.

Acids and their conjugate bases accumulate in or dissipate from the interstitial space when tissue perfusion does not match the metabolic demand. Extracellular acidosis dilates most arterial beds, but associated acid-base disturbances-e.g., intracellular acidification and decreases in HCO3- concentration-can also elicit pro-contractile influences that diminish vasodilation and even dominate in some vascular beds to cause vasoconstriction. The ensemble activities of the acid-base-sensitive reactions in vascular smooth muscle and endothelial cells optimize vascular resistance for blood pressure control and direct the perfusion towards active tissue. In this review, we describe the mechanisms of intracellular pH regulation in the vascular wall and discuss how vascular smooth muscle and endothelial cells sense acid-base disturbances. We further deliberate on the functional effects of local acid-base disturbances and their integrated cardiovascular consequences under physiological and pathophysiological conditions. Finally, we address how mutations and polymorphisms in the molecular machinery that regulates pH locally and senses acid-base disturbances in the vascular wall can result in cardiovascular disease. Based on the emerging molecular insight, we propose that targeting local pH-dependent effectors-rather than systemic acid-base disturbances-has therapeutic potential to interfere with the progression and reduce the severity of cardiovascular disease.