Another market segment: sport event tourism by disabled athletes.

Sports and tourism are connected in various parts of economies, cultures, and nations. However, there has been a limited understanding of sports event tourism involving disabled athletes. This study explored the behavioral and socio-demographic implications of the disabled sports event tourism and investigated the motivational factors involved. An in-person survey was administered to 108 disabled athletes who attended the summer and winter Paralympics. A Structural Equation Model was used to determine the association between the factors of life satisfaction, emotional happiness, escapism, perceived value, and future intention, using the Monte Carlo parametric bootstrapping method to test significance of direct and indirect effects. Cronbach was acceptable because it exceeds 0.70 which satisfies the cut-off of confirmatory factor analysis. In addition, the individual values of average variance extracted (AVE), were greater than 0.50 (0.72) which meets the requirement and the convergent validity of all the constructs. The results showed that life satisfaction had a significant direct effect on future intentions. Emotional happiness had a significant direct effect on the perceived value of an event. Escapism had significant direct effects on perceived value and future intentions. Perceived value significantly influenced future intentions. The relationship between emotional happiness and future intention was fully mediated by perceived value. However, the relationship between escapism and future intention was only partially mediated by perceived value. The results of this study are valuable for developing future management and marketing policies for disabled athletes and tourists to advance the existing sports event tourism and disabled athlete's behavior studies.

Comparison of Finasteride and Dutasteride on Risk of Prostate Cancer in Patients with Benign Prostatic Hyperplasia: A Pooled Analysis of 15 Real-world Databases.

PURPOSE: Finasteride and dutasteride are used to treat benign prostatic hyperplasia (BPH) and reduce the risk of developing prostate cancer. Finasteride blocks only the type 2 form of 5-alpha-reductase, whereas dutasteride blocks both type 1 and 2 forms of the enzyme. Previous studies suggest the possibility that dutasteride may be superior to finasteride in preventing prostate cancer. We directly compared the effects of finasteride and dutasteride on the risk of prostate cancer in patients with BPH using a pooled analysis of 15 real-world databases. MATERIALS AND METHODS: We conducted a multicenter, cohort study of new-users of finasteride and dutasteride. We include patients who were prescribed 5 mg finasteride or dutasteride for the first time to treat BPH and had at least 180 days of prescription. We excluded patients with a history of prostate cancer or a prostate-specific antigen level ≥ 4 ng/mL before the study drug prescription. Cox regression analysis was performed to examine the hazard ratio (HR) for prostate cancer after propensity score (PS) matching. RESULTS: A total of 8,284 patients of new-users of finasteride and 8,670 patients of new-users of dutasteride were included across the 15 databases. In the overall population, compared to dutasteride, finasteride was associated with a lower risk of prostate cancer in both on-treatment and intent-to-treat time-at-risk periods. After 1:1 PS matching, 4,897 patients using finasteride and 4,897 patients using dutasteride were enrolled in the present study. No significant differences were observed for risk of prostate cancer between finasteride and dutasteride both on-treatment (HR=0.66, 95% confidence interval [CI]: 0.44-1.00; p=0.051) and intent-to-treat time-at-risk periods (HR=0.87, 95% CI: 0.67-1.14; p=0.310). CONCLUSIONS: Using real-world databases, the present study demonstrated that dutasteride was not associated with a lower risk of prostate cancer than finasteride in patients with BPH.

Biodegradable Polymer Versus Polymer-Free Ultrathin Sirolimus-Eluting Stents: Analysis of the Stent Arm Registry From the HOST-IDEA Randomized Trial.

BACKGROUND: The efficacy and safety of each third-generation drug-eluting stent with ultrathin struts and advanced polymer technology remain unclear. We investigated the clinical outcomes of percutaneous coronary intervention using the Coroflex ISAR polymer-free sirolimus-eluting stent (SES) or Orsiro biodegradable polymer SES. METHODS: The HOST-IDEA trial (Harmonizing Optimal Strategy for Treatment of Coronary Artery Stenosis-Coronary Intervention With Next-Generation Drug-Eluting Stent Platforms and Abbreviated Dual Antiplatelet Therapy), initially designed with a 2×2 factorial approach, sought to randomize patients undergoing percutaneous coronary intervention based on dual antiplatelet therapy duration (3 versus 12 months) and stent type (Coroflex ISAR versus Orsiro). Despite randomizing 2013 patients for dual antiplatelet therapy duration, the stent arm transitioned to a registry format during the trial. Among these, 328 individuals (16.3%) were randomized for Coroflex ISAR or Orsiro SES, while 1685 (83.7%) underwent percutaneous coronary intervention without stent-type randomization. In this study, the Coroflex ISAR (n=559) and Orsiro groups (n=1449) were matched using a propensity score. The prespecified primary end point was target lesion failure, a composite of cardiac death, target vessel myocardial infarction, and clinically driven target lesion revascularization at 12 months. RESULTS: The baseline patient and procedural characteristics were well balanced between the Coroflex ISAR and Orsiro groups after propensity score matching (n=559, each group). The Coroflex ISAR group was significantly associated with a higher rate of target lesion failure, mainly driven by clinically driven target lesion revascularization, compared with the Orsiro group (3.4% versus 1.1%; hazard ratio, 3.21 [95% CI, 1.28-8.05]; P=0.01). A higher risk of target lesion failure in the Coroflex ISAR group was consistently observed across various subgroups. The rates of any bleeding (hazard ratio, 0.85 [95% CI, 0.51-1.40]; P=0.52) and major bleeding (hazard ratio, 1.58 [95% CI, 0.61-4.08]; P=0.34) were comparable between the 2 groups. CONCLUSIONS: In this propensity score-matched analysis of the stent arm registry from the HOST-IDEA trial, the Orsiro SES was associated with significantly better outcomes in terms of 1-year target lesion failure, mainly driven by clinically driven target lesion revascularization, than the Coroflex ISAR SES. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02601157.

The structural and mechanistic bases for the viral resistance to allosteric HIV-1 integrase inhibitor pirmitegravir.

Allosteric HIV-1 integrase (IN) inhibitors (ALLINIs) are investigational antiretroviral agents which potently impair virion maturation by inducing hyper-multimerization of IN and inhibiting its interaction with viral genomic RNA. The pyrrolopyridine-based ALLINI pirmitegravir (PIR) has recently advanced into Phase 2a clinical trials. Previous cell culture based viral breakthrough assays identified the HIV-1(Y99H/A128T IN) variant that confers substantial resistance to this inhibitor. Here, we have elucidated the unexpected mechanism of viral resistance to PIR. While both Tyr99 and Ala128 are positioned within the inhibitor binding V-shaped cavity at the IN catalytic core domain (CCD) dimer interface, the Y99H/A128T IN mutations did not substantially affect direct binding of PIR to the CCD dimer or functional oligomerization of full-length IN. Instead, the drug-resistant mutations introduced a steric hindrance at the inhibitor mediated interface between CCD and C-terminal domain (CTD) and compromised CTD binding to the CCDY99H/A128T + PIR complex. Consequently, full-length INY99H/A128T was substantially less susceptible to the PIR induced hyper-multimerization than the WT protein, and HIV-1(Y99H/A128T IN) conferred >150-fold resistance to the inhibitor compared to the WT virus. By rationally modifying PIR we have developed its analog EKC110, which readily induced hyper-multimerization of INY99H/A128T in vitro and was ~14-fold more potent against HIV-1(Y99H/A128T IN) than the parent inhibitor. These findings suggest a path for developing improved PIR chemotypes with a higher barrier to resistance for their potential clinical use.

Structure-based functional analysis of a novel NADPH-producing glyceraldehyde-3-phosphate dehydrogenase from Corynebacterium glutamicum.

Corynebacterium glutamicum is an industrial workhorse applied in the production of valuable biochemicals. In the process of bio-based chemical production, improving cofactor recycling and mitigating cofactor imbalance are considered major solutions for enhancing the production yield and efficiency. Although, glyceraldehyde-3-phosphate dehydrogenase (GapDH), a glycolytic enzyme, can be a promising candidate for a sufficient NADPH cofactor supply, however, most microorganisms have only NAD-dependent GapDHs. In this study, we performed functional characterization and structure determination of novel NADPH-producing GapDH from C. glutamicum (CgGapX). Based on the crystal structure of CgGapX in complex with NADP cofactor, the unique structural features of CgGapX for NADP stabilization were elucidated. Also, N-terminal additional region (Auxiliary domain, AD) appears to have an effect on enzyme stabilization. In addition, through structure-guided enzyme engineering, we developed a CgGapX variant that exhibited 4.3-fold higher kcat, and 1.2-fold higher kcat/KM values when compared with wild-type. Furthermore, a bioinformatic analysis of 100 GapX-like enzymes from 97 microorganisms in the KEGG database revealed that the GapX-like enzymes possess a variety of AD, which seem to determine enzyme stability. Our findings are expected to provide valuable information for supplying NADPH cofactor pools in bio-based value-added chemical production.

Highly efficient site-specific protein modification using tyrosinase from Streptomyces avermitilis: Structural insight.

Tyrosinase-mediated protein conjugation has recently drawn attention as a site-specific protein modification tool under mild conditions. However, the tyrosinases reported to date act only on extremely exposed tyrosine residues, which limits where the target tyrosine can be located. Herein, we report a tyrosinase from Streptomyces avermitilis (SaTYR), that exhibits a much higher activity against tyrosine residues on the protein surface than other tyrosinases. We determined the crystal structure of SaTYR and revealed that the enzyme has a relatively flat and shallow substrate-binding pocket to accommodate a protein substrate. We demonstrated SaTYR-mediated fluorescence dye tagging and PEGylation of a surface tyrosine residue that was unreacted by other tyrosinases with an approximately 95.2 % conjugation yield in 1 h. We also present a structural rationale that considers the steric hindrance from adjacent residues and surrounding structures along with the extent of solvent exposure of residues, as necessary when determining the optimal positions for introducing target tyrosine residues in SaTYR-mediated protein modification. The study demonstrated that the novel tyrosinase, SaTYR, extends the scope of tyrosinase-mediated protein modification, and we propose that site-specific tyrosine conjugation using SaTYR is a promising strategy for protein bioconjugation in various applications.

Structural and Biochemical Analysis of 3-Dehydroquinate Dehydratase from Corynebacterium glutamicum.

Dehydroquinate dehydratase (DHQD) catalyzes the conversion of 3-dehydroquinic acid (DHQ) into 3-dehydroshikimic acid in the mid stage of the shikimate pathway, which is essential for the biosynthesis of aromatic amino acids and folates. Here, we report two the crystal structures of type II DHQD (CgDHQD) derived from Corynebacterium glutamicum, which is a widely used industrial platform organism. We determined the structures for CgDHQDWT with the citrate at a resolution of 1.80Å and CgDHQDR19A with DHQ complexed forms at a resolution of 2.00 Å, respectively. The enzyme forms a homododecamer consisting of four trimers with three interfacial active sites. We identified the DHQ-binding site of CgDHQD and observed an unusual binding mode of citrate inhibitor in the site with a half-opened lid loop. A structural comparison of CgDHQD with a homolog derived from Streptomyces coelicolor revealed differences in the terminal regions, lid loop, and active site. Particularly, CgDHQD, including some Corynebacterium species, possesses a distinctive residue P105, which is not conserved in other DHQDs at the position near the 5-hydroxyl group of DHQ. Replacements of P105 with isoleucine and valine, conserved in other DHQDs, caused an approximately 70% decrease in the activity, but replacement of S103 with threonine (CgDHQDS103T) caused a 10% increase in the activity. Our biochemical studies revealed the importance of key residues and enzyme kinetics for wild type and CgDHQDS103T, explaining the effect of the variation. This structural and biochemical study provides valuable information for understanding the reaction efficiency that varies due to structural differences caused by the unique sequences of CgDHQD.

Novel piperazine-based ionizable lipid nanoparticles allow the repeated dose of mRNA to fibrotic lungs with improved potency and safety.

mRNA-based protein replacement therapy has received much attention as a novel intervention in clinical disease treatment. Lipid nanoparticles (LNPs) are widely used for their therapeutic potential to efficiently deliver mRNA. However, clinical translation has been hampered by the immunogenicity of LNPs that may aggravate underlying disease states. Here, we report a novel ionizable LNP with enhanced potency and safety. The piperazine-based biodegradable ionizable lipid (244cis) was developed for LNP formulation and its level of protein expression and immunogenicity in the target tissue was evaluated. It was found that 244cis LNP enabled substantial expression of the target protein (human erythropoietin), while it minimally induced the secretion of monocyte chemoattractant protein 1 (MCP-1) as compared to other conventional LNPs. Selective lung targeting of 244cis LNP was further investigated in tdTomato transgenic mice with bleomycin-induced pulmonary fibrosis (PF). The repeated administration of 244cis LNP with Cre recombinase mRNA achieved complete transfection of lung endothelial cells (~80%) and over 40% transfection of Sca-1-positive fibroblasts. It was shown that 244cis LNP allows the repeated dose of mRNA without the loss of activity due to its low immunogenicity. Our results demonstrate that 244cis LNP has great potential for the treatment of chronic diseases in the lungs with improved potency and safety.

Moderate-intensity statin plus ezetimibe vs high-intensity statin according to baseline LDL-C in the treatment of atherosclerotic cardiovascular disease: A post-hoc analysis of the RACING randomized trial.

BACKGROUND AND AIMS: Whether the effect of a combination strategy rather than increasing doses of one drug to lower low-density lipoprotein cholesterol (LDL-C) levels is consistent across baseline LDL-C levels remains uncertain. METHODS: In the RACING trial, which showed a non-inferiority of moderate-intensity statin with ezetimibe (rosuvastatin 10 mg with ezetimibe 10 mg) to high-intensity statin (rosuvastatin 20 mg) for the primary outcome (3-year composite of cardiovascular death, major cardiovascular event, or stroke), the heterogeneity in treatment effect according to baseline LDL-C levels was assessed for the primary and secondary outcomes (clinical efficacy and safety). RESULTS: Of 3780 participants, 2817 participants (74.5%) had LDL-C <100 mg/dL, and 963 participants (25.5%) had LDL-C ≥100 mg/dL. The treatment effect of combination therapy versus high-intensity statin monotherapy was similar among the lower LDL-C subset (8.8% vs. 10.2%; hazard ratio [HR] 0.85, 95% confidence interval [CI] 0.67 to 1.08, p = 0.19) and the higher LDL-C subset (10.8% vs. 9.6 %; HR 1.14, 95% CI 0.76 to 1.7, p = 0.53) without a significant interaction (interaction p = 0.22). Of the secondary outcomes, the 1-, 2-, and 3-year achievement of LDL-C <70 mg/dL was greater in the combination therapy group regardless of baseline LDL-C levels. CONCLUSIONS: Among ASCVD patients, there was no heterogeneity in the effect of moderate-intensity statin plus ezetimibe combination therapy in the higher and lower baseline LDL-C levels for the 3-year composite of cardiovascular outcomes.

Structure-Guided Protein Engineering of Glyceraldehyde-3-phosphate Dehydrogenase from Corynebacterium glutamicum for Dual NAD/NADP Cofactor Specificity.

Since the discovery of l-glutamate-producing Corynebacterium glutamicum, it has evolved to be an industrial workhorse. For biobased chemical production, suppling sufficient amounts of the NADPH cofactor is crucial. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH), a glycolytic enzyme that converts glyceraldehyde-3-phosphate (G3P) to 1,3-bisphosphoglycerate and produces NADH, is a major prospective solution for the cofactor imbalance issue. In this study, we determined the crystal structure of GAPDH from C. glutamicum ATCC13032 (CgGAPDH). Based on the structural information, we generated six CgGAPDH variants, CgGAPDHL36S, CgGAPDHL36S/T37K, CgGAPDHL36S/T37K/P192S, CgGAPDHL36S/T37K/F100V/P192S, CgGAPDHL36S/T37K/F100L/P192S, and CgGAPDHL36S/T37K/F100I/P192S, that can produce both NADH and NAPDH. The final CgGAPDHL36S/T37K/F100V/P192S variant showed a 212-fold increase in enzyme activity for NADP as well as 200% and 30% increased activity for the G3P substrate under NAD and NADP cofactor conditions, respectively. In addition, crystal structures of CgGAPDH variants in complex with NAD(P) permit the elucidation of differences between wild-type CgGAPDH and variants in relation to cofactor stabilization.

Structural and Biochemical Studies on Product Inhibition of S-Adenosylmethionine Synthetase from Corynebacterium glutamicum.

S-Adenosylmethionine (SAM) acts as a methyl donor in living organisms, and S-adenosylmethionine synthetase (MetK) is an essential enzyme for cells, as it synthesizes SAM from methionine and adenosine triphosphate (ATP). This study determined the crystal structures of the apo form and adenosine/triphosphate complex form of MetK from Corynebacterium glutamicum (CgMetK). Results showed that CgMetK has an allosteric inhibitor binding site for the SAM product in the vicinity of the active site and is inhibited by SAM both competitively and noncompetitively. Through structure-guided protein engineering, the CgMetKE68A variant was developed that exhibited an almost complete release of inhibition by SAM with rather enhanced enzyme activity. The crystal structure of the CgMetKE68A variant revealed that the formation of a new hydrogen bond between Tyr66 and Glu102 by the E68A mutation disrupted the allosteric SAM binding site and also improved the protein thermal stability by strengthening the tetramerization of the enzyme.

Thalidomide and a Dipeptidyl Peptidase 4 Inhibitor in a Rat Model of Experimental Autoimmune Myocarditis.

BACKGROUND AND OBJECTIVES: Myocarditis is a potentially fatal disease, but curative treatments have not yet been established. Myocardial inflammation is an important pathogenesis of this disease, and immunosuppressants such as methylprednisolone and immunoglobulin have been used for treatment; however, the effectiveness needs to be improved. Thalidomide and dipeptidyl peptidase (DPP) 4 inhibitors were recently investigated regarding their immunomodulatory properties. This study aimed to test whether thalidomide or a DPP4 inhibitor (evogliptin) can improve the effectiveness of myocarditis treatment using a rat model of experimental autoimmune myocarditis (EAM). METHODS: Rats with or without myocarditis were administered thalidomide at 100 mg/kg/day and DPP4 inhibitor at 10 mg/kg/day orally. Measurement of echocardiography, serum inflammatory cytokines, myocardial histopathological examination, and immunohistochemical staining for leukocytes, macrophages, CD4+ T cells, and cytoskeleton were performed after 3 weeks, and the fibrosis area was measured after 3 and 6 weeks. RESULTS: Thalidomide and DPP4 inhibitor did not reduce the severity of myocarditis compared with the EAM without treatment rats by comparing the echocardiographic data, myocardial CD4+, macrophages, neutrophil infiltrations, and the heart weight/body weight ratio in 3 weeks. The levels of inflammatory cytokines were not lower in the thalidomide and DPP4 inhibitor-treated group than in the untreated group in 3 weeks. In 6 weeks, thalidomide and DPP4 inhibitors did not reduce the fibrosis area compared to untreated groups. CONCLUSIONS: Although thalidomide and the DPP4 inhibitor had an immunomodulatory effect and are used against inflammatory diseases, they did not ameliorate myocardial inflammation and fibrosis in this rat model of EAM.

Sex difference in the age-related decline of global longitudinal strain of left ventricle.

Global longitudinal strain (GLS) is a valuable indicator of subclinical myocardial dysfunction. Whether the effect of aging on subclinical left ventricular dysfunction is sex-specific is not well documented. This study aimed to identify age-related changes in GLS according to sex in patients with a normal left ventricular ejection fraction (LVEF). In this cross-sectional, single-center cohort study in Korea, participants who underwent GLS measurement using 2D speckle-tracking echocardiography were retrospectively reviewed, and participants with normal LVEF (≥ 55%) without documented cardiovascular disease were included. Reduced GLS was defined as absolute values below 18%. Of 682 study participants (mean age, 58; female, 51.5%), 209 (30.6%) had reduced GLS. Females with reduced GLS were older than those with normal GLS (68 vs. 58 years, P < 0.001); with no difference of age in males (55 vs. 57 years; P = 0.265). Univariate analysis showed age to correlate significantly with reduced GLS only in female (r = - 0.364; P < 0.001). In multivariable analysis, female > 66 years old had significantly higher risk of reduced GLS (Odds ratio 2.66; 95% CI 1.22-5.76; P = 0.014). In participants with normal LVEF, GLS decreased with age in females but not in males. Particularly, females aged 66 years and older had a significantly higher risk of reduced GLS. These findings suggest that GLS could be a valuable parameter for assessing subclinical cardiac dysfunction, especially in older females.

Impact of the circadian nuclear receptor REV-ERBα in dorsal raphe 5-HT neurons on social interaction behavior, especially social preference.

Social interaction among conspecifics is essential for maintaining adaptive, cooperative, and social behaviors, along with survival among mammals. The 5-hydroxytryptamine (5-HT) neuronal system is an important neurotransmitter system for regulating social behaviors; however, the circadian role of 5-HT in social interaction behaviors is unclear. To investigate whether the circadian nuclear receptor REV-ERBα, a transcriptional repressor of the rate-limiting enzyme tryptophan hydroxylase 2 (Tph2) gene in 5-HT biosynthesis, may affect social interaction behaviors, we generated a conditional knockout (cKO) mouse by targeting Rev-Erbα in dorsal raphe (DR) 5-HT neurons (5-HTDR-specific REV-ERBα cKO) using the CRISPR/Cas9 gene editing system and assayed social behaviors, including social preference and social recognition, with a three-chamber social interaction test at two circadian time (CT) points, i.e., at dawn (CT00) and dusk (CT12). The genetic ablation of Rev-Erbα in DR 5-HTergic neurons caused impaired social interaction behaviors, particularly social preference but not social recognition, with no difference between the two CT points. This deficit of social preference induced by Rev-Erbα in 5-HTDR-specific mice is functionally associated with real-time elevated neuron activity and 5-HT levels at dusk, as determined by fiber-photometry imaging sensors. Moreover, optogenetic inhibition of DR to nucleus accumbens (NAc) 5-HTergic circuit restored the impairment of social preference in 5-HTDR-specific REV-ERBα cKO mice. These results suggest the significance of the circadian regulation of 5-HT levels by REV-ERBα in regulating social interaction behaviors.

Three-directional engineering of IsPETase with enhanced protein yield, activity, and durability.

The mesophilic PETase from Ideonella sakaiensis (IsPETase) has been shown to exhibit high PET hydrolysis activity, but its low stability limits its industrial applications. Here, we developed a variant, Z1-PETase, with enhanced soluble protein yield and durability while maintaining or improving activity at lower temperatures. The selected Z1-PETase not only exhibited a 20-fold improvement in soluble protein yield compared to the previously engineered IsPETaseS121E/D186H/S242T/N246D (4p) variant, but also demonstrated a 30% increase in low-temperature activity at 40 °C, along with an 11 °C increase in its TmD value. The PET depolymerization test across a temperature range low to high (30-70 °C) confirmed that Z1-PETase exhibits high accessibility of mesophilic PET hydrolase and rapid depolymerizing rate at higher temperature in accordance with the thermal behaviors of polymer and enzyme. Additionally, structural interpretation indicated that the stabilization of specific active site loops in Z1-PETase contributes to enhanced thermostability without adversely impacting enzymatic activity. In a pH-stat bioreactor, Z1-PETase depolymerized > 90% of both transparent and colored post-consumer PET powders within 24 and 8 h at 40 °C and 55 °C, respectively, demonstrating that the utility of this IsPETase variant in the bio-recycling of PET.

Discovery and rational engineering of PET hydrolase with both mesophilic and thermophilic PET hydrolase properties.

Excessive polyethylene terephthalate (PET) waste causes a variety of problems. Extensive research focused on the development of superior PET hydrolases for PET biorecycling has been conducted. However, template enzymes employed in enzyme engineering mainly focused on IsPETase and leaf-branch compost cutinase, which exhibit mesophilic and thermophilic hydrolytic properties, respectively. Herein, we report a PET hydrolase from Cryptosporangium aurantiacum (CaPETase) that exhibits high thermostability and remarkable PET degradation activity at ambient temperatures. We uncover the crystal structure of CaPETase, which displays a distinct backbone conformation at the active site and residues forming the substrate binding cleft, compared with other PET hydrolases. We further develop a CaPETaseM9 variant that exhibits robust thermostability with a Tm of 83.2 °C and 41.7-fold enhanced PET hydrolytic activity at 60 °C compared with CaPETaseWT. CaPETaseM9 almost completely decompose both transparent and colored post-consumer PET powder at 55 °C within half a day in a pH-stat bioreactor.

Crystal Structures of 6-Phosphogluconate Dehydrogenase from Corynebacterium glutamicum.

Corynebacterium glutamicum (C. glutamicum) has been considered a very important and meaningful industrial microorganism for the production of amino acids worldwide. To produce amino acids, cells require nicotinamide adenine dinucleotide phosphate (NADPH), which is a biological reducing agent. The pentose phosphate pathway (PPP) can supply NADPH in cells via the 6-phosphogluconate dehydrogenase (6PGD) enzyme, which is an oxidoreductase that converts 6-phosphogluconate (6PG) to ribulose 5-phosphate (Ru5P), to produce NADPH. In this study, we identified the crystal structure of 6PGD_apo and 6PGD_NADP from C. glutamicum ATCC 13032 (Cg6PGD) and reported our biological research based on this structure. We identified the substrate binding site and co-factor binding site of Cg6PGD, which are crucial for understanding this enzyme. Based on the findings of our research, Cg6PGD is expected to be used as a NADPH resource in the food industry and as a drug target in the pharmaceutical industry.

Molecular mechanism underlying high-affinity terephthalate binding and conformational change of TBP from Ideonella sakaiensis.

Ideonella sakaiensis is the bacterium that can survive by degrading polyethylene terephthalate (PET) plastic, and terephthalic acid (TPA) binding protein (IsTBP) is an essential periplasmic protein for uptake of TPA into the cytosol for complete degradation of PET. Here, we demonstrated that IsTBP has remarkably high specificity for TPA among 33 monophenolic compounds and two 1,6-dicarboxylic acids tested. Structural comparisons with 6-carboxylic acid binding protein (RpAdpC) and TBP from Comamonas sp. E6 (CsTphC) revealed the key structural features that contribute to high TPA specificity and affinity of IsTBP. We also elucidated the molecular mechanism underlying the conformational change upon TPA binding. In addition, we developed the IsTBP variant with enhanced TPA sensitivity, which can be expanded for the use of TBP as a biosensor for PET degradation.

Cryo-EM structure of bifunctional malonyl-CoA reductase from Chloroflexus aurantiacus reveals a dynamic domain movement for high enzymatic activity.

The platform chemical 3-hydroxypropionic acid is used to synthesize various valuable materials, including bioplastics. Bifunctional malonyl-CoA reductase is a key enzyme in 3-hydroxypropionic acid biosynthesis as it catalyzes the two-step reduction of malonyl-CoA to malonate semialdehyde to 3-hydroxypropionic acid. Here, we report the cryo-EM structure of a full-length malonyl-CoA reductase protein from Chloroflexus aurantiacus (CaMCRFull). The EM model of CaMCRFull reveals a tandem helix architecture comprising an N-terminal (CaMCRND) and a C-terminal (CaMCRCD) domain. The CaMCRFull model also revealed that the enzyme undergoes a dynamic domain movement between CaMCRND and CaMCRCD due to the presence of a flexible linker between these two domains. Increasing the flexibility and extension of the linker resulted in a twofold increase in enzyme activity, indicating that for CaMCR, domain movement is crucial for high enzyme activity. We also describe the structural features of CaMCRND and CaMCRCD. This study reveals the protein structures underlying the molecular mechanism of CaMCRFull and thereby provides valuable information for future enzyme engineering to improve the productivity of 3-hydroxypropionic acid.

Deployment of an electrocorticography system with a soft robotic actuator.

Electrocorticography (ECoG) is a minimally invasive approach frequently used clinically to map epileptogenic regions of the brain and facilitate lesion resection surgery and increasingly explored in brain-machine interface applications. Current devices display limitations that require trade-offs among cortical surface coverage, spatial electrode resolution, aesthetic, and risk consequences and often limit the use of the mapping technology to the operating room. In this work, we report on a scalable technique for the fabrication of large-area soft robotic electrode arrays and their deployment on the cortex through a square-centimeter burr hole using a pressure-driven actuation mechanism called eversion. The deployable system consists of up to six prefolded soft legs, and it is placed subdurally on the cortex using an aqueous pressurized solution and secured to the pedestal on the rim of the small craniotomy. Each leg contains soft, microfabricated electrodes and strain sensors for real-time deployment monitoring. In a proof-of-concept acute surgery, a soft robotic electrode array was successfully deployed on the cortex of a minipig to record sensory cortical activity. This soft robotic neurotechnology opens promising avenues for minimally invasive cortical surgery and applications related to neurological disorders such as motor and sensory deficits.