Acid Research Articles

Bempedoic Acid's Chemistry, Pharmacological Characteristics and Bioanalytical Techniques: An Updated Review

Background: Elevated blood cholesterol has been established as a major risk factor for atherosclerotic cardiovascular disease (ASCVD). Adults with hyperlipidemia have a significantly increased risk of developing cardiovascular diseases (CVD). First-line treatments for hyperlipidemia include statins, which help raise HDL-C levels in cases of severe and familial hypercholesterolemia and decrease LDL-C and TG levels. Numerous adverse effects on muscles have been associated with statins, such as asymptomatic elevations in blood creatine kinase activity and potentially fatal rhabdomyolysis. Non-statin drugs are advised for people whose very high cardiovascular risk or heterozygous familial hypercholesterolemia make statin therapy insufficient. A novel lipid-lowering medication with a distinct mode of action is bempedoic acid. Elevated blood cholesterol is a significant risk factor for atherosclerotic cardiovascular disease (ASCVD). Individuals with hyperlipidemia are at a higher risk for developing cardiovascular diseases. Statins are the primary treatment for hyperlipidemia, raising HDL-C levels and lowering LDL-C and TG levels. However, statins can adversely affect muscles, including muscle-related complications like increased blood creatine kinase activity and rhabdomyolysis. Therefore, nonstatin drugs may be recommended for individuals. Bempedoic acid is a brand-new, first-in-class, oral small molecule that inhibits cholesterol manufacturing like statins, consequently reducing lowdensity lipoprotein cholesterol (LDL-C) through activating LDL receptors. Methods: This study offers helpful information on how to utilize bempedoic acid to decrease LDLC, as well as recommendations for which individuals could benefit and safety monitoring tips during therapy. A novel family of drugs called bempedoic acid is identified as a prodrug that becomes bempedoyl- CoA in the liver via an enzyme called very longchain consisting of acyl-CoA synthetase 1. Bempedoic acid can control cholesterol metabolism. Low-density lipoprotein cholesterol levels appeared to be dramatically reduced by bempedoic acid, according to clinical investigations. The toleration of bempedoic acid was good. Results: A cardiovascular outcomes trial is now evaluating bempedoic acid to determine its impact on major cardiovascular events in patients with or at high risk for cardiovascular disease and statin intolerance. Conclusion: This review describes the chemistry, mechanism of action, pharmacokinetics, analytical potential, and safety of bempedoic acid. Bempedoic acid is an effective and often well-tolerated drug used to further reduce LDL-C levels in patients taking the maximum dosage of tolerated statins or to control LDL-C levels in persons who can not take statins. The results of the clear Outcomes research, which is looking into whether bempedoic acid might reduce the frequency of serious cardiovascular events, are expected in 2025.

Amphiphilic Oligonucleotide Derivatives-Promising Tools for Therapeutics.

Recent advances in genetics and nucleic acid chemistry have created fundamentally new tools, both for practical applications in therapy and diagnostics and for fundamental genome editing tasks. Nucleic acid-based therapeutic agents offer a distinct advantage of selectively targeting the underlying cause of the disease. Nevertheless, despite the success achieved thus far, there remain unresolved issues regarding the improvement of the pharmacokinetic properties of therapeutic nucleic acids while preserving their biological activity. In order to address these challenges, there is a growing focus on the study of safe and effective delivery methods utilising modified nucleic acid analogues and their lipid bioconjugates. The present review article provides an overview of the current state of the art in the use of chemically modified nucleic acid derivatives for therapeutic applications, with a particular focus on oligonucleotides conjugated to lipid moieties. A systematic analysis has been conducted to investigate the ability of amphiphilic oligonucleotides to self-assemble into micelle-like structures, as well as the influence of non-covalent interactions of such derivatives with serum albumin on their biodistribution and therapeutic effects.

Effect of modifiers on the stability of 1‑butyl‑3-methylimidazolium-based ionic liquids

The distinctive capabilities of 1‑butyl‑3-methylimidazolium (bmim) cation-based ionic liquids (ILs) to dissolve lignocellulosic biomass offer the potential for the development of novel green bioprocessing technologies based on their utilization as green solvents. The limited range of thermal stability of ILs necessitates the use of various co-solvents to maintain solubility. In the present study, an original approach to determine the degree of degradation of alkylimidazolium ILs was proposed, based on the application of gravimetric analysis method to determine the content of volatile degradation products and high-performance liquid chromatography-high-resolution mass spectrometry (HPLCHRMS) to determine the total degree of degradation. The proposed approach, as well as the combination of HPLCHRMS with gas chromatography-mass spectrometry (GC–MS), was employed to comprehensively characterize the impact of additives and impurities (water, dimethyl sulfoxide, hydrochloric and acetic acids, diethylamine) on the degradation of bmim acetate, chloride, and methyl sulfate during thermal treatment under typical biomass dissolution conditions (150 °C, 24 h). The presence of additives or impurities in the composition of ILs has been found to predominantly contribute to a decrease in the number of volatile compounds formed, while increasing the variety and relative content of non-volatile degradation products. The use of protic solvents and acids results in a decrease in the overall degree of degradation of ionic liquids and in the fraction of volatile compounds formed. This allows for the classification of binary mixtures based on these additives as "green" solvents at temperatures below 150 °C.

Post Tungsten CMP Cleaning: Optimization for Cleaning Efficiency and Corrosion Reduction

Tungsten chemical-mechanical planarization (W CMP) is among the first applications of the CMP process implemented in high volume semiconductor manufacturing. Alkaline chemicals such as diluted NH4OH have been the predominant choice of post W CMP clean due to charge repulsion between W and dielectric/abrasive surface in high pH. However, W dissolution occurs spontaneously above pH ∼ 4.0. Consequently, W corrosion can happen during post-CMP cleaning. From that perspective, acidic chemistry (e.g., pH < 4.0) seems a more benign choice to protect W, although at such low pH, isoelectric potential curves suggest coulombic attraction between W and oxide/silica surfaces, making it unfavorable for particle removal. The above pH dilemma for post-CMP cleaning and W protection can be managed by adding corrosion inhibitor to an alkaline chemical. Results from blanket and patterned wafers suggest reduction in surface defects and W dissolution can be accomplished simultaneously by an alkaline clean chemical with corrosion inhibitor (pH ∼ 9.78), which shows high cleaning efficiency and reduced W loss than citric acid-based chemical (pH ∼ 2.66), DIW, and diluted NH4OH. In addition, we show that DIW alone can induce severe W dissolution in features of fine geometry. Possible counter measures against such DIW-induced W corrosion are discussed.

SYNTHESIS AND CHARACTERIZATION OF POLYEPICHLOROHYDRIN DIOLS

Polyepichlorohydrin (PECH) is a functional polymer with high value in energy materials. Cationic ring-opening polymerization of epichlorohydrin (ECH) with a diol initiator and Lewis or protic acids catalyst, proceeds through an activated monomer mechanism (AM) allowing control of the polymer's average molecular weight and polydispersity index. In the present investigation, PECH diol was synthesized under the catalysis of boron trifluoride etherate, with the ECH monomer:ethylene glycol as an initiator molar ratio of 1:0.045, achieving a low molecular weight nM = 1935 g/mol, low polydispersity index PDI = 1.25, predominantly in the linear chain configuration with the terminal hydroxyl group.

The scent gland composition of the Mangshan pit viper, Protobothrops mangshanensis.

The Mangshan pit viper, Protobothrops mangshanensis, is a rare, highly endangered snake native to the mountainous regions of Hunan Province in China. Snakes possess abdominal scent glands, which have been chemically studied in several species. These glands can contain various lipids and peptides, but very often also complex mixtures of carboxylic acids. We report here the occurrence of novel methyl-branched unsaturated acids found in the secretions of six captive individuals living in a zoo. The structures of these compounds, 4.6-dimethylalk-5-enoates in a homologous series from C11-C16, were characterized by GC-MS and GC-IR analysis and various microderivatization reactions including hydrogenation and esterification leading to methyl and pyridylmethyl esters. In addition, dimethyloxazoline formation helped to localize the double bond. The synthesis of methyl 4,6-dimethyldodec-5-enoate allowed the correct assignment of structures and showed the (E)-configuration of the double bond for the major naturally occurring diastereomers. These acids occur in small amounts compared to the major glandular components, cholesterol, and 1-O-hexadecylglycerol, as well as other common long-chain alcohols and amides. Although a general defensive function has been proposed for snake abdominal scent glands, the specific chemistry and moderate amounts of acids reported here may suggest a function in chemical signaling for the Mangshan pit viper. In addition, proline-containing diketopiperazines were identified for the first time in snake scent glands, although an artificial formation from amino acids likely present in the secretion cannot be excluded.

Versatile synthesis of 2-functionalized dihydrothiazolo[2,3-b]quinazolines through regioselective electrophilic intramolecular heterocyclization of 3-alkenyl-2-thioxoquinazolin-4-ones

Electrophilic intramolecular heterocyclizations of 3-alkenyl-2-thioxoquinazolin-4-ones, induced by halogens, NBS, sulfuryl chloride, protic acids, selenium, or tellurium halides, proceed with high regioselectivity. This process leads to the formation of 2-functionalized dihydrothiazolo[2,3-b]quinazolines, showcasing the versatility and reliability of this synthetic route across various electrophilic reagents.

Modulating Electrostatic Properties and Noncovalent Interactions via Structural Isomerism: The Microwave Spectra and Molecular Structures of (E)- and (Z)-1,2,3,3,3-Pentafluoropropene and Their Gas-Phase Heterodimers with the Argon Atom.

Microwave spectra of both the E and Z isomers of 1,2,3,3,3-pentafluoropropene along with all three of the singly substituted 13C isotopologues for each are obtained using broadband chirped-pulse Fourier transform microwave spectroscopy from 2.0-18.1 GHz. Associated quantum chemistry calculations show that the barrier to internal rotation of the CF3 group is significantly higher for the Z isomer, which is stabilized by an intramolecular hydrogen bond, although the barriers in both isomers are sufficiently high to prevent the observation of any effects due to internal rotation. The normal isotopologues of the argon heterodimers for both isomers are also observed in the broadband spectrum and a Balle-Flygare cavity Fourier transform microwave spectrometer is used to obtain the 5.0-20.6 GHz spectra of the corresponding 13C isotopologues. In each case, the argon atom locates so as to maximize its interactions with areas of significant electron density. However, mapped electrostatic potential surfaces indicate that the areas of greatest nucleophilicity are different for the two isomers, suggesting that they may interact differently in forming heterodimers with protic acids.

Responses of soil microbial metabolism, function and soil quality to long-term addition of organic materials with different carbon sources

Biochar and green manure have been widely applied in agricultural production and are important means to achieve sustainable agriculture. However, there is limited research systematically and comprehensively exploring the response of soil microbiota and the changes in soil metabolomics after the addition of two different carbon source amendments to the soil, and the differential mechanisms of soil metabolomics between them remain unclear. In this study, a long-term field experiment (initiated in 2019) was conducted to investigate the effects of biochar and green manure application on soil nutrients and soil functions driven by soil microbes. Compared to the pure fertilizer treatment, biochar increased soil total carbon by 14.54% to 27.04% and soil available potassium by 4.67% to 27.46%. Ryegrass significantly increased soil available phosphorus and organic matter. Under different fertilization regimes, the ecological niches of soil microbes changed significantly. Network analysis revealed that long-term ryegrass returning reduced the complexity of soil microbial networks. Ryegrass and biochar increased dispersal limitation in fungal assemblages (reaching 93.33% and 86.67%, respectively), with biochar particularly enhancing variable selection in bacterial assemblages (accounting for 53.33%). Variation partitioning analysis based on redundancy analysis indicated that humic substances had the highest explanatory power for microbial community variation, with humic substances explaining 38.49% of bacteria and 52.19% of fungi variation. The ryegrass treatment mainly changed the abundance of carbohydrates (CH), amines (AM), c (AH), and lipids (LP), while the BC treatment mainly altered the abundance of organic acids (AC), amines (AM), and carbohydrates (CH). Meanwhile, both treatments significantly reduced the bisphenol A, one of the soil pollutants. Ryegrass incorporation significantly increased the abundance of genes related to soil C, N, P, and S cycling, especially genes involved in carbon decomposition, while biochar significantly enhanced the abundance of nitrogen fixation genes nifH and Hao in soil. Random forest model results indicated that carbohydrates, alcohols, aromatics (AR), and ester (ES) were the main categories of metabolites in soil influenced by differential microbes, and Finegoldia served as a common important metabolic driving species. In summary, this study reveals the processes of soil function, microbial community succession, and metabolism driven by ryegrass and biochar, providing important insights for optimizing soil management and improving soil quality.Graphical

Solvatochromic and biological studies of new meso-benzodioxole-BODIPY-2-Schiff dye

This paper focuses on solvatochromic studies of a new synthesised BODIPY dye with piperonal and ortho-hydroxy aryl Schiff base substituents (BD-2-Schiff). The studied dye has been analysed by spectroscopic and computational techniques to have a deep insight into the impact of the solvents’ polarity and the specific interactions on the dye characteristics. The synthesized dye turns to be sensitive to external specific interactions, caused by protic solvents and acid, which change spectral characteristics of BODIPY-2-Schiff. The calculations by the density functional theory (DFT) and the time-dependent density functional theory (TD-DFT) have been accomplished for the interpretation of the obtained experimental results. The synthesized dye has been evaluated as a photosensitizer for the light induced inactivation of Staphylococcus aureus (S. aureus) and Acinetobacter baumannii (A. baumannii). The synthesized BODIPY dye has shown a significant photocidal activity (above 90 %) against these pathogenic bacteria at low microgram concentrations and excitation with low doses of visible light (0.72 J/cm2; λ = 519 nm).

Molecular studies of Allographa effusosoredica sp. nov. (Graphidaceae) along with its Trentepohlia photobiont and a comprehensive checklist for Indian Allographa

The current study describes a new species, Allographa effusosoredica, from the Western Ghats, India, along with its Trentepohlia photobiont. This study is based on morphological, chemical and molecular analyses using mtSSU, LSU and RPB2 sequence data for Allographa effusosoredica mycobiont and ITS sequence data for Trentepohlia photobiont. Allographa effusosoredica is characterized by a thin effuse thallus with diffuse soredia, 8-spored asci, transversely 7–11 septate ascospores, and norstictic acid chemistry. It is surprisingly similar to the widespread Graphis glaucescens, which differs in the absence of soredia and norstictic acid, but clusters phylogenetically within Allographa, allied to Allographa xanthospora, making the limits between Allographa and the distantly related genus Graphis more diffuse and raising doubts about the correct placement of G. glaucescens. The photobiont of the novel species is allied to Trentepohlia cf. arborum HZ-2017 isolate YN1047. This is the first species of Allographa sequenced from India.

Investigation of transverse exchange-springs in electrodeposited nano-heterostructured films through first-order reversal curve analysis

The prerequisite of efficient exchange-spring nano-heterostructures, i.e., tuning both hard and soft phases at a nanometer level, has posed significant preparation challenges to ensure effective exchange-coupling. Here, we present a novel approach to fabricate transverse exchange-spring nano-heterostructures using single starting material through an “in situ” electrodeposition technique at room temperature. Utilizing modified acidic bath chemistry and controlled hydrogen evolution, we successfully prepared stress-free, shiny, fine-grained amorphous, and nanocrystalline Co-rich cobalt phosphorus films. These nano-heterostructured films exhibit a unique non-collinear anisotropy-driven transverse exchange-spring behavior, investigated systematically under ambient conditions. The comprehensive functional analyses reveal that intricate interplay between in-plane (IP) anisotropy of amorphous phase and out-of-plane (OOP) anisotropy generating from a nanocrystalline structure compete with each other, while producing characteristic stripe domain structures to novel corrugated stripe domain shapes. The angle-dependent first-order reversal curve distributions demonstrate new insights into the magnetic reversal mechanisms, further confirming the non-exchange-spring and exchange-spring nature of the films depending on the prevalent interfacial exchange coupling. Formation of anisotropy-driven metastable-state due to competition between IP and OOP anisotropy at a particular OOP orientation has led the normal exchange-spring structures to a transverse exchange-spring structure. Micromagnetic simulations, in excellent agreement with experimental data, further elucidate the formation of characteristic stripe domain patterns and the influence of anisotropy on the magnetic properties. The innovative methodology and detailed functional analysis presented here offer significant understanding to the field of exchange-spring magnetic materials, including anisotropy-driven metastable states, demonstrating the potential for scalable and cost-effective fabrication of advanced nano-heterostructures with tailored magnetic properties.

Development of a Shigella conjugate vaccine targeting Shigella flexneri 6 that is immunogenic and provides protection against virulent challenge

Immunity protective against shigella infection targets the bacterial O-specific polysaccharide (OSP) component of lipopolysaccharide. A multivalent shigella vaccine would ideally target the most common global Shigella species and serotypes such as Shigella flexneri 2a, S. flexneri 3a, S. flexneri 6, and S. sonnei. We previously reported development of shigella conjugate vaccines (SCVs) targeting S. flexneri 2a (SCV-Sf2a) and 3a (SCV-Sf3a) using a platform squaric acid chemistry conjugation approach and carrier protein rTTHc, a 52 kDa recombinant protein fragment of the heavy chain of tetanus toxoid. Here we report development of a SCV targeting S. flexneri 6 (SCV-Sf6) using the same platform approach. We demonstrated that SCV-Sf6 was recognized by serotype-specific monoclonal antibodies and convalescent sera of humans recovering from shigellosis in Bangladesh, suggesting correct immunological display of OSP. We vaccinated mice and found induction of serotype-specific OSP and LPS IgG and IgM responses, as well as rTTHc-specific IgG responses. Immune responses were increased when administered with aluminum phosphate adjuvant. Vaccination induced bactericidal antibody responses against S. flexneri 6, and vaccinated animals were protected against lethal challenge with virulent S. flexneri 6. Our results assist in the development of a multivalent vaccine protective against shigellosis.

Optimising CNT-FET biosensor design through modelling of biomolecular electrostatic gating and its application to β-lactamase detection

Carbon nanotube field effect transistors (CNT-FET) hold great promise as next generation miniaturised biosensors. One bottleneck is modelling how proteins, with their distinctive electrostatic surfaces, interact with the CNT-FET to modulate conductance. Using advanced sampling molecular dynamics combined with non-canonical amino acid chemistry, we model protein electrostatic potential imparted on single walled CNTs (SWCNTs). We focus on using β-lactamase binding protein (BLIP2) as the receptor as it binds the antibiotic degrading enzymes, β-lactamases (BLs). BLIP2 is attached via the single selected residue to SWCNTs using genetically encoded phenyl azide photochemistry. Our devices detect two different BLs, TEM-1 and KPC-2, with each BL generating distinct conductance profiles due to their differing surface electrostatic profiles. Changes in conductance match the model electrostatic profile sampled by the SWCNTs on BL binding. Thus, our modelling approach combined with residue-specific receptor attachment could provide a general approach for systematic CNT-FET biosensor construction.

Prevention of ischemic stroke in patients with myeloproliferative neoplasms

Introduction. Myeloproliferative neoplasms (MPNs) are a rare but significant cause of strokes.Aim. To describe risk factors for stroke development, as well as prevention strategies based on available literature data on patients with MPN.Main findings. Online databases (PubMed, E-Library) were searched for studies on cerebral thrombotic complications in the setting of myeloproliferative disorders. Induction of specific cytoreductive treatment with low doses of acetylsalicylic ac id should be considered as a mandatory component of secondary prevention of noncardioembolic stroke.

The Effects of Internal Curing and Shrinkage Cracking Avoidance on the Corrosion of Reinforced Concrete Walls with Superabsorbent Polymers

The pursuit of durable and sustainable construction has driven interest in innovative materials, with superabsorbent polymers (SAPs) emerging as a promising solution, especially for the concrete industry. SAPs offer significant benefits to the durability of concrete structures, including mitigation of autogenous shrinkage, enhanced freeze–thaw resistance, crack sealing, and stimulation of autogenous healing. This study focuses on the impact of internal curing with SAPs on crack formation and corrosion initiation in large-scale reinforced concrete walls (14 m × 2.75 m × 0.8 m). Both commercial SAPs based on acrylic acid chemistry and in-house-developed SAPs based on alginates were evaluated. Key findings reveal that the reference wall exhibited visible cracking just five days after casting, while the SAP-treated wall remained crack-free throughout a 24-month monitoring period. Moreover, the reference wall showed corrosion initiation at two locations near the cracks within six months, whereas the SAP-treated wall exhibited no signs of corrosion potential. Laboratory tests further demonstrated a slight reduction in chloride penetration and carbonation in SAP-treated specimens compared to the reference. These results highlight the efficacy of SAPs in enhancing the durability and longevity of reinforced concrete structures.

Enhanced protection for interfacial lipid ozonolysis by sulfur-containing amino acids

Sulfur-containing amino acids have been proposed as drugs for lipid oxidation associated with diseases for a long time, but the molecular-level mechanism on the effectiveness of sulfur-containing amino acids against lipid oxidation remains elusive. In this work, with the interfacial sensitivity mass spectrometry method, oxidation of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidylglycerol (POPG), a widely used model lipid, was significantly inhibited on hung droplet surface in presence of sulfur-containing amino acids, such as cysteine (Cys) and methionine (Met). Both the Cys and Met showed a self-sacrificing protection. The amino acids with −S-R tails (R referring to methyl or t-butyl group) showed more effective against POPG oxidation than those with −SH tails, and this process was not related to the conformations of amino acids. The low effectiveness of Cys during the interfacial chemistry was proved to arise from the formation of disulfide bond. This study extends the current understanding of chemistry of sulfur-containing amino acids and provides insights to aid the sulfur-containing amino acids against cell oxidation.

A Visual Compendium of Principal Modifications within the Nucleic Acid Sugar Phosphate Backbone.

Nucleic acid chemistry is a huge research area that has received new impetus due to the recent explosive success of oligonucleotide therapy. In order for an oligonucleotide to become clinically effective, its monomeric parts are subjected to modifications. Although a large number of redesigned natural nucleic acids have been proposed in recent years, the vast majority of them are combinations of simple modifications proposed over the past 50 years. This review is devoted to the main modifications of the sugar phosphate backbone of natural nucleic acids known to date. Here, we propose a systematization of existing knowledge about modifications of nucleic acid monomers and an acceptable classification from the point of view of chemical logic. The visual representation is intended to inspire researchers to create a new type of modification or an original combination of known modifications that will produce unique oligonucleotides with valuable characteristics.

Native Characterization of Noncanonical Nucleic Acid Thermodynamics via Programmable Dynamic DNA Chemistry.

Folding thermodynamics, quantitatively described using parameters such as ΔGfold°, ΔHfold°, and ΔSfold°, is essential for characterizing the stability and functionality of noncanonical nucleic acid structures but remains difficult to measure at the molecular level. Leveraging the programmability of dynamic deoxyribonucleic acid (DNA) chemistry, we introduce a DNA-based molecular tool capable of performing a free energy shift assay (FESA) that directly characterizes the thermodynamics of noncanonical DNA structures in their native environments. FESA operates by the rational design of a reference DNA probe that is energetically equivalent to a target noncanonical nucleic acid structure in a series of toehold-exchange reactions, yet is structurally incapable of folding. As a result, a free energy shift (ΔΔGrxn°) is observed when plotting the reaction yield against the free energy of each toehold-exchange. We mathematically demonstrated that ΔGfold°, ΔHfold°, and ΔSfold° of the analyte can be calculated based on ΔΔGrxn°. After validating FESA using six DNA hairpins by comparing the measured ΔGfold°, ΔHfold°, and ΔSfold° values against predictions made by NUPACK software, we adapted FESA to characterize noncanonical nucleic acid structures, encompassing DNA triplexes, G-quadruplexes, and aptamers. This adaptation enabled the successful characterization of the folding thermodynamics for these complex structures under various experimental conditions. The successful development of FESA marks a paradigm shift and a technical advancement in characterizing the thermodynamics of noncanonical DNA structures through molecular tools. It also opens new avenues for probing fundamental chemical and biophysical questions through the lens of molecular engineering and dynamic DNA chemistry.

The Nitroplast and Its Relatives Support a Universal Model of Features Predicting Gene Retention in Endosymbiont and Organelle Genomes.

Endosymbiotic relationships have shaped eukaryotic life. As endosymbionts coevolve with their host, toward full integration as organelles, their genomes tend to shrink, with genes being completely lost or transferred to the host nucleus. Modern endosymbionts and organelles show diverse patterns of gene retention, and why some genes and not others are retained in these genomes is not fully understood. Recent bioinformatic study has explored hypothesized influences on these evolutionary processes, finding that hydrophobicity and amino acid chemistry predict patterns of gene retention, both in organelles across eukaryotes and in less mature endosymbiotic relationships. The exciting ongoing elucidation of endosymbiotic relationships affords an independent set of instances to test this theory. Here, we compare the properties of retained genes in the nitroplast, recently reported to be an integrated organelle, two related cyanobacterial endosymbionts that form "spheroid bodies" in their host cells, and a range of other endosymbionts, with free-living relatives of each. We find that in each case, the symbiont's genome encodes proteins with higher hydrophobicity and lower amino pKa than their free-living relative, supporting the data-derived model predicting the retention propensity of genes across endosymbiont and organelle genomes.