Flexibility of Binding Site is Essential to the Ca2+ Selectivity in EF-Hand Calcium-Binding Proteins.

High binding affinity and selectivity of metal ions are essential to the function of metalloproteins. Thus, understanding the factors that determine these binding characteristics is of major interest for both fundamental mechanistic investigations and guiding of the design of novel metalloproteins. In this work, we perform QM cluster model calculations and quantum mechanics/molecular mechanics (QM/MM) free energy simulations to understand the binding selectivity of Ca2+ and Mg2+ in the wild-type carp parvalbumin and its mutant. While a nonpolarizable MM model (CHARMM36) does not lead to the correct experimental trend, treatment of the metal binding site with the DFTB3 model in a QM/MM framework leads to relative binding free energies (ΔΔGbind) comparable with experimental data. For the wild-type (WT) protein, the calculated ΔΔGbind is ∼6.6 kcal/mol in comparison with the experimental value of 5.6 kcal/mol. The good agreement highlights the value of a QM description of the metal binding site and supports the role of electronic polarization and charge transfer to metal binding selectivity. For the D51A/E101D/F102W mutant, different binding site models lead to considerable variations in computed binding affinities. With a coordination number of seven for Ca2+, which is shown by QM/MM metadynamics simulations to be the dominant coordination number for the mutant, the calculated relative binding affinity is ∼4.8 kcal/mol, in fair agreement with the experimental value of 1.6 kcal/mol. The WT protein is observed to feature a flexible binding site that accommodates a range of coordination numbers for Ca2+, which is essential to the high binding selectivity for Ca2+ over Mg2+. In the mutant, the E101D mutation reduces the flexibility of the binding site and limits the dominant coordination number of Ca2+ to be seven, thereby leading to reduced binding selectivity against Mg2+. Our results highlight that the binding selectivity of metal ions depends on both the structural and dynamical properties of the protein binding site.

Causal Association between Tea Intake and Acute Cerebrovascular Events: A Multivariate Mendelian Randomized Study in European Populations.

BACKGROUND: Numerous research works have investigated the association between tea consumption and the risk of acute cerebrovascular events; however, the results are inconsistent. OBJECTIVES: We used Mendelian randomization (MR) to evaluate the causal association between tea intake and several acute cerebrovascular events, including any ischemic stroke, large atherosclerotic stroke (LAS), cardiogenic embolic stroke (CES), small vessel stroke (SVS), intracranial hemorrhage (ICH), and subarachnoid hemorrhage (SAH). METHODS: We obtained summary genome-wide association study (GWAS) data on tea intake and acute cerebrovascular events in populations of European ancestry. The GWAS on tea intake is derived from the UK Biobank, where we have chosen single-nucleotide polymorphisms (SNPs) closely associated with it as instrumental variables. We also obtained summary data on ischemic stroke from a GWAS meta-analysis, as well as summary data on ICH and SAH from the FinnGen study. We first explored the causal association between tea intake and several acute cerebrovascular events using univariate Mendelian randomization (UVMR), and then further assessed the causal association between tea intake and SVS using multivariate Mendelian randomization (MVMR) corrected for multiple confounders. RESULTS: In UVMR, genetically predicted increases in tea intake were linked to a lower risk of SVS (OR: 0.58; 95% CI: 0.39, 0.86). There was no causal association between tea intake and the risk of other acute cerebrovascular events. In the MVMR, our results show that there was still a significant causal association between drinking tea and SVS, after adjusting body mass index, total cholesterol, low-density lipoprotein cholesterol, diabetes, hypertension, smoking, and alcohol consumption. CONCLUSION: This MR study provides new genetic evidence that increased tea intake reduces the risk of SVS in the European population. However, possibly because of limited statistical power, the study did not find that tea consumption reduced the risk of several other acute cerebrovascular events.

Causal association between plant foods intake and Alzheimer's disease: a Mendelian randomization study.

BACKGROUND: Alzheimer's disease (AD) is a degenerative disease of the nervous system. Observational studies have found an association between plant food intake and AD. However, it is unclear whether this association is influenced by confounding factors. We aimed to explore the causal relationship between plant-based diet and the risk of AD using two-sample Mendelian randomization. MATERIALS AND METHODS: We obtained datasets of exposure from the IEU Open GWAS project, including dried fruit intake, fresh fruit intake, raw vegetable intake, cooked vegetable intake, and cereal intake. The summary data for AD were obtained from a large GWAS meta-analysis containing 71,880 cases and 383,378 controls. RESULTS: Increased intake of dried fruits was associated with a reduced risk of AD (IVW: OR = 0.88, 95CI = 0.82-0.95). No causal association was found between the intake of other foods and AD. CONCLUSION: This MR study suggests that genetically predicted increased intake of dried fruits is a causal protective factor for AD.

Diet and risk of low back pain: a Mendelian randomization analysis.

PURPOSE: Previous epidemiological and other studies have shown an association between diet and low back pain (LBP). This study aimed to investigate the causal relationship between diet and LBP using a Mendelian randomization (MR) approach. METHODS: The three main methods in this study were weighted median, MR-Egger, and inverse variance weighting (IVW). We utilized MR-PRESSO to eliminate abnormal SNPs. Additionally, tests for pleiotropy and heterogeneity were conducted. Utilizing IVW and MR-Egger's Cochran's Q test, heterogeneity was evaluated. MR-Egger intercepts were used in pleiotropy tests. A leave-one-out analysis was also used to evaluate the stability of the study's findings. RESULTS: The frequency of alcohol intake was associated with an increased risk of LBP. Increased processed meat intake, dried fruit intake, cereal intake, and tea intake were causally associated with a decreased risk of LBP (alcohol intake frequency: odds ratio (OR) = 1.28; 95% confidence interval (CI), 1.11-1.47; P = 0.0006; processed meat intake: OR = 0.60, 95%CI 0.39-0.92, P = 0.019; dried fruit intake: OR = 0.43, 95%CI 0.29-0.66, P = 0.00008; cereal intake: OR = 0.62, 95%CI 0.42-0.92, P = 0.018; tea intake: OR = 0.75, 95%CI 0.58-0.97, P = 0.029). Heterogeneity and pleiotropy were also not found in the sensitivity analysis. The leave-one-out analysis also showed more robust results. Other dietary intakes were not causally associated with LBP. CONCLUSIONS: This two-sample MR study found that frequency of alcohol intake was associated with an increased risk of LBP, and intake of processed meat, dried fruit, cereals, and tea was associated with a decreased risk of LBP. Moreover, no causal relationship was found with LBP in the other 13 diets.

Hypothyroidism's effect on stroke limited to specific subtypes: A Mendelian randomization study.

BACKGROUND: The association between hypothyroidism and stroke remains controversial and the association between hypothyroidism and stroke subtypes has not been satisfactorily researched. This study aimed to explore the causal effect of hypothyroidism on the risk of stroke and its subtypes by Mendelian randomization (MR) analysis. METHODS: Single nucleotide polymorphisms (SNPs) were selected from published genome-wide association studies (GWAS) meta-analysis as instrumental variables (IVs) for hypothyroidism. As outcomes, summary GWAS data for stroke and its subtypes were obtained from two other large GWAS meta-analyses, including any stroke (AS), any ischemic stroke (AIS), large vessel stroke (LAS), cardiogenic embolic stroke (CES), small vessel stroke (SVS), and intracranial hemorrhage (ICH). Univariate Mendelian randomization (UVMR) and multivariate Mendelian randomization (MVMR) were used to assess the causal effect of hypothyroidism on stroke and its subtypes. RESULTS: In UVMR, genetically predicted hypothyroidism was significantly associated with LAS (OR = 1.14, 95CI = 1.02-1.27) and SVS (OR = 1.14, 95CI = 1.04-1.25), but not with AS, AIS, CES, and ICH. The results of the MVMR showed that after adjusting for smoking, alcohol consumption, hypertension, diabetes, low-density lipoprotein cholesterol (LDL-c), and body mass index (BMI), the causal association between hypothyroidism and SVS remained significant, while the association between hypothyroidism and LAS became nonsignificant. CONCLUSION: Hypothyroidism is causally associated with risk for LAS and SVS, but not for other stroke subtypes. Hypothyroidism may be an independent risk factor for SVS, and vascular risk factors play an important role in hypothyroidism causing LAS.

Selective modulation of alkali metal ions on acetylcholinesterase.

Acetylcholinesterase (AChE) is an important hydrolase in cholinergic synapses and a candidate target in the treatment of Alzheimer's disease. The lithium treatment widely used in neurological disorders can alter the AChE activity, yet the underlying mechanism of how the ion species regulate the enzymatic activity remains unclear. In this work, we performed combined quantum mechanics/molecular mechanics (QM/MM) and molecular dynamics (MD) simulations and well-tempered metadynamics to understand the modulation of human AChE (hAChE) activity using three alkali metal ions (Li+, Na+, and K+) in different concentrations. Our simulations show that the binding affinity and catalytic activity are affected by different ion species through allosteric ion coordination geometries on the hAChE complex and distant electrostatic screening effect. A Li+ cluster involving D330, E393, and D397 residues and three Li+ ions was found to be highly conserved and can be critical to the enzyme activity. Binding energy calculations indicate that the electrostatic screening from allosterically bound cations can affect the key residues at the catalytic site and active-site gorge, including E199. Furthermore, an increase in ion concentration can lead to lower reactivity, especially for Li+ ions, which exhibit more cation-hAChE contacts than Na+ and K+. The selective ion binding and their preferred modulation on hAChE are highly related to ion species. This work provides a molecular perspective on selective modulation by different ion species of the enzyme catalytic processes.

How to Stabilize Carbenes in Enzyme Active Sites without Metal Ions.

Carbenes are highly reactive compounds with unique value to synthetic chemistry. However, a small number of natural enzymes have been shown to utilize carbene chemistry, and artificial enzymes engineered with directed evolution required transition metal ions to stabilize the carbene intermediates. To facilitate the design of broader classes of enzymes that can take advantage of the rich carbene chemistry, it is thus important to better understand how to stabilize carbene species in enzyme active sites without metal ions. Motivated by our recent studies of the anaerobic ergothioneine biosynthesis enzyme EanB, we examine carbene-protein interaction with both cluster models and QM/MM simulations. The cluster calculations find that an N-heterocyclic carbene interacts strongly with polar and positively charged protein motifs. In particular, the interaction between a guanidinium group and carbene is as strong as ∼30 kcal/mol, making arginine a great choice for the preferential stabilization of carbenes. We also compare the WT EanB and its mutant in which the key tyrosine was replaced by a non-natural analogue (F2Tyr) using DFTB3/MM simulations. The calculations suggest that the carbene intermediate in the F2Tyr mutant is more stable than that in the WT enzyme by ∼3.5 kcal/mol, due to active site rearrangements that enable a nearby arginine to better stabilize the carbene in the mutant. Overall, the current work lays the foundation for the pursuit of enzyme designs that can take advantage of the unique chemistry offered by carbenes without the requirement of metal ions.

Improvement of d-d interactions in density functional tight binding for transition metal ions with a ligand field model: assessment of a DFTB3+U model on nickel coordination compounds.

To improve the description of interactions among the localized d, f electrons in transition metals, we have introduced a ligand-field motivated contribution into the Density Functional Tight Binding (DFTB) model. Referred to as DFTB3+U, the approach treats the d, f electron repulsions with rotationally invariant orbital-orbital interactions and a Hartree-Fock model; this represents a major conceptual improvement over the original DFTB3 approach, which treats the d, f-shell interactions in a highly averaged fashion without orbital level of description. The DFTB3+U approach is tested using a series of nickel compounds that feature Ni(ii) and Ni(iii) oxidation states. By using parameters developed with the original DFTB3 Hamiltonian and empirical +U parameters (F0/2/4 Slater integrals), we observe that the DFTB3+U model indeed provides substantial improvements over the original DFTB3 model for a number of properties of the nickel compounds, including the population and spin polarization of the d-shell, nature of the frontier orbitals, ligand field splitting and the energy different between low and high spin states at OPBE optimized structures. This proof-of-concept study suggests that with self-consistent parameterization of the electronic and +U parameters, the DFTB3+U model can develop into a promising model that can be used to efficiently study reactive events involving transition metals ion condensed phase systems. The methodology can be integrated with other approximate QM methods as well, such as the extended tight binding (xTB) approach.

Composition and charge state influence on the ion-neutral collision cross sections of protonated N-linked glycopeptides: an experimental and theoretical deconstruction of coulombic repulsion vs. charge solvation effects.

Ion mobility spectrometry (IMS) is of significant interest as a platform for glycoanalysis. While much attention has been focused on the resolution of isomeric carbohydrates and glycoconjugates, another appealing aspect of IMS is the ability to sort different classes of biomolecules into distinct regions of mass vs. mobility space. This capability has potential to greatly simplify glycoproteomic analyses, as glycosylated and non-glycosylated peptides can be rapidly partitioned in the gas phase. Nevertheless, the physical and chemical characteristics of glycopeptides that dictate their mass vs. mobility loci have yet to be systematically investigated. This report presents an IMS study of model protonated glycopeptide ions with systematically varied oligosaccharide topologies, polypeptide sequences, and charge states. In all, over 110 ion-neutral collision cross sections (CCSs) were measured and analyzed in the context of the physicochemical characteristics of the analytes. Glycan size and composition emerged as a decisive factor in dictating the CCS space occupied by the glycopeptides and exerted this influence in a charge state dependent fashion. Furthermore, elongation of the glycan group was found to either increase or decrease glycopeptide CCSs depending on the ion charge state and the size of the glycan. Molecular dynamics (MD) simulations of the gas phase structures and CCSs of selected glycopeptides revealed that the experimental observations were consistent with a glycan size and charge state dependent interplay between destabilizing coulombic repulsion effects (tending to result in more extended structures) and stabilizing charge solvation effects in which the glycan plays a major role (tending to result in more compact structures). Taken together, these IMS and MD findings suggest the possibility of predicting and delineating glycopeptide-enriched regions of mass vs. mobility space for applications in glycoproteomics.

Catalytic Mechanism of Amyloid-ß Peptide Degradation by Insulin Degrading Enzyme: Insights from Quantum Mechanics and Molecular Mechanics Style Møller-Plesset Second Order Perturbation Theory Calculation.

Insulin degrading enzyme (IDE), a metalloprotease that degrades amyloid-ß (Aß) peptides and insulin, is associated with Alzheimer's disease and diabetes. The mechanism of IDE catalyzed degrading of Aß peptides, which is of fundamental importance in the design of therapeutic methods for Alzheimer's disease, has not been fully understood. In this work, combined quantum mechanics and molecular mechanics (QM/MM) style Møller-Plesset second order perturbation theory (MP2) geometry optimization calculations are performed to investigate the catalytic mechanism of the Aß40 Phe19-Phe20 peptide bond cleavage by human IDE. The analyses using QM/MM MP2 optimization suggest that a neutral water molecule is at the active site of the enzyme-substrate (ES) complex. The water molecule is in hydrogen bonding with the nearby anionic Glu111 of IDE but not directly bound to the catalytic Zn ion. This is confirmed by QM/MM DFTB3 molecular dynamics simulation. Our studies also reveal that the hydrolysis of the Aß40 Phe19-Phe20 peptide bond by IDE consists of four key steps. The neutral water is first activated by moving toward and binding to the Zn ion. A gem-diol intermediate is then formed by the activated neutral water molecule attacking the C atom of the Phe19-Phe20 peptide bond. The next is the protonation of the N atom of Phe19-Phe20 peptide bond to form an intermediate with an elongated C-N bond. The final step is the breaking of the Phe19-Phe20 C-N bond. The final step is the rate-determining step with a calculated Gibbs free energy of activation of 17.34 kcal/mol, in good agreement with the experimental value 16.7 kcal/mol. This mechanism provides the basis for the design of biochemical methods to modulate the activity of IDE in humans.

Molecular dynamics simulation of ion mobility in gases.

A force field molecular dynamics method is developed to directly simulate ion drift in buffer gases driven by an electric field. The ion mobility and collision cross sections (CCSs) with relevance to ion mobility spectrometry can be obtained from the simulated drift velocity in high-density buffer gases (pressure ∼50 bars) and high electric fields (∼107 V/m). Compared to trajectory methods, the advantage of the molecular dynamics method is that it can simultaneously sample the internal dynamic motions of the ion and the ion-gas collisions. For ions with less than 100 atoms, the simulated collision cross section values can be converged to within ±1%-2% by running a 100 ns simulation for 5-19 h using one computer core. By using a set of element-based Lennard-Jones parameters that are not tuned for different atomic types in different molecules, the simulated collision cross sections for 15 small molecular ions (number of atoms ranging from 17 to 85, mass ranging from 74.1 to 609.4 g/mol) are consistent with experimental values: the mean unsigned error is 2.6 Å2 for He buffer gas and 4.4 Å2 for N2 buffer gas. The sensitivity of the simulated CCS values to random diffusion, drift velocity, electric field strength, temperature, and buffer gas density is examined.

Improved Photoinduced Fluorogenic Alkene-Tetrazole Reaction for Protein Labeling.

The 1,3-dipolar cycloaddition reaction between an alkene and a tetrazole represents one elegant and rare example of fluorophore-forming bioorthogonal chemistry. This is an attractive reaction for imaging applications in live cells that requires less intensive washing steps and/or needs spatiotemporal resolutions. In the present work, as an effort to improve the fluorogenic property of the alkene-tetrazole reaction, an aromatic alkene (styrene) was investigated as the dipolarophile. Over 30-fold improvement in quantum yield of the reaction product was achieved in aqueous solution. According to our mechanistic studies, the observed improvement is likely due to an insufficient protonation of the styrene-tetrazole reaction product. This finding provides useful guidance to the future design of alkene-tetrazole reactions for biological studies. Fluorogenic protein labeling using the styrene-tetrazole reaction was demonstrated both in vitro and in vivo. This was realized by the genetic incorporation of an unnatural amino acid containing the styrene moiety. It is anticipated that the combination of styrene with different tetrazole derivatives can generally improve and broaden the application of alkene-tetrazole chemistry in real-time imaging in live cells.

Chemoselective Alteration of Fluorophore Scaffolds as a Strategy for the Development of Ratiometric Chemodosimeters.

Ratiometric sensors generally couple binding events or chemical reactions at a distal site to changes in the fluorescence of a core fluorophore scaffold. However, such approaches are often hindered by spectral overlap of the product and reactant species. We provide a strategy to design ratiometric sensors that display dramatic spectral shifts by leveraging the chemoselective reactivity of novel functional groups inserted within fluorophore scaffolds. As a proof-of-principle, fluorophores containing a borinate (RF620 ) or silanediol (SiOH2R) functionality at the bridging position of the xanthene ring system are developed as endogenous H2 O2 sensors. Both these fluorophores display far-red to near-infrared excitation and emission prior to reaction. Upon oxidation by H2 O2 both sensors are chemically converted to tetramethylrhodamine, producing significant (≥66 nm) blue-shifts in excitation and emission maxima. This work provides a new concept for the development of ratiometric probes.

Molecular identification and functional characterisation of the interferon regulatory factor 1 in the blunt snout bream (Megalobrama amblycephala).

Interferon regulatory factors (IRFs) play a key role in mediating the host response against pathogen infection and other important biological processes. This is the first report of an IRF family member in blunt snout bream Megalobrama amblycephala. The complete cDNA of M. amblycephala (Ma) IRF1 gene has 1422 nucleotides (nt.), with an open reading frame of 858 nt, encoding a polypeptide of 285 amino acids. The putative MaIRF1 polypeptide shared significant structural homology with known IRF1 homologs: a conserved IRF domain was found at the N-terminal and an IRF association domain 2 at the C-terminal. Phylogenetic analysis showed that MaIRF1 amino acid sequence clustered with other teleost IRF1s, with a grass carp ortholog exhibiting the highest similarity. MaIRF1 mRNA expression patterns were studied using quantitative real-time PCR in healthy fish tissues and after a challenge with Aeromonas hydrophila bacterium. It was constitutively expressed in all examined tissues: the highest in blood, the lowest in muscle. The expression after A. hydrophila challenge was up-regulated in liver, spleen and kidney, but down-regulated in intestine and gills. At the protein level, similar expression patterns were observed in liver and gills. Patterns differed in intestine (up-regulation), spleen (down-regulation) and kidney (expression mostly unchanged). This study indicates that MaIRF1 gene plays an important role in the blunt snout bream immune system, hence providing an important base for further studies.

The 8-silyloxyquinoline scaffold as a versatile platform for the sensitive detection of aqueous fluoride.

Utilizing a novel 8-silyloxyquinoline scaffold, we demonstrate the ability to synthesize fluorogenic probes for the sensitive and selective detection of inorganic fluoride (NaF) in aqueous samples. Our initial probe design (2) is capable of detecting inorganic fluoride at levels as low as 3.8 µM (72 ppb) in aqueous solutions, well below PHS recommended levels for drinking water (0.7-1.2 ppm), placing this probe among the most sensitive fluoride sensors reported to date. Furthermore, our results highlight the utility of the readily modifiable 8-silyloxyquinoline scaffold for the design of tailored fluoride sensing platforms. We demonstrate the ability to rationally tune the fluorescence and physical properties of the 8-silyloxyquinoline scaffold, producing a red-shifted fluoride probe (4) capable of detecting 50 µM (0.95 ppm) NaF in aqueous samples using a straightforward test-strip-based assay format. Taken together this work provides a template for the design of fluoride sensors capable of reporting on relevant concentrations of fluoride in the laboratory and in the field.

Causal relationship between diet and knee osteoarthritis: A Mendelian randomization analysis.

BACKGROUND: Knee osteoarthritis (KOA) is a common disabling joint disease that affects millions of people worldwide. Diet may play a role in the etiology and progression of KOA, but evidence for a causal relationship is limited. We aimed to investigate the causal impact of dietary intake on KOA risk using Mendelian randomization (MR). METHODS: We used summary-level data from genome-wide association studies (GWAS) including dietary intake (n = 335, 394-462, 342), and KOA (n = 403, 124). We selected 6-77 genetic variants as instrumental variables for 18 dietary factors, including processed meat, poultry, beef, oily fish, non-oily fish, pork, lamb, frequency of alcohol intake, alcoholic beverages, tea, coffee, dried fruit, cereals, cheese, bread, cooked vegetables, salad/raw vegetables, and fresh fruit. We performed univariate and multivariate MR analyses to estimate the causal effect of each dietary factor on KOA risk. We also performed some sensitivity analyses to assess the validity of the MR hypothesis. RESULTS: We found that higher coffee intake was associated with increased KOA risk, whereas higher intake of dried fruits, grains, cheese, and oily fish was associated with reduced KOA risk. After multivariate adjustment, we found that coffee and oily fish intake may affect KOA through obesity, body mass index (BMI), diabetes, hypertension, and prolonged standing. Sensitivity analyses did not reveal any evidence of pleiotropy. CONCLUSIONS: Our study provides new causal evidence that dietary intake may influence KOA risk. Specifically, we suggest that increased intake of dried fruits, grains, cheese, and oily fish and decreased coffee intake may be beneficial in preventing and mitigating KOA. further studies are needed to elucidate the underlying mechanisms and to confirm our findings in different populations.

Assessing the utility of artificial intelligence throughout the triage outpatients: a prospective randomized controlled clinical study.

Currently, there are still many patients who require outpatient triage assistance. ChatGPT, a natural language processing tool powered by artificial intelligence technology, is increasingly utilized in medicine. To facilitate and expedite patients' navigation to the appropriate department, we conducted an outpatient triage evaluation of ChatGPT. For this evaluation, we posed 30 highly representative and common outpatient questions to ChatGPT and scored its responses using a panel of five experienced doctors. The consistency of manual triage and ChatGPT triage was assessed by five experienced doctors, and statistical analysis was performed using the Chi-square test. The expert ratings of ChatGPT's answers to these 30 frequently asked questions revealed 17 responses earning very high scores (10 and 9.5 points), 7 earning high scores (9 points), and 6 receiving low scores (8 and 7 points). Additionally, we conducted a prospective cohort study in which 45 patients completed forms detailing gender, age, and symptoms. Triage was then performed by outpatient triage staff and ChatGPT. Among the 45 patients, we found a high level of agreement between manual triage and ChatGPT triage (consistency: 93.3-100%, p<0.0001). We were pleasantly surprised to observe that ChatGPT's responses were highly professional, comprehensive, and humanized. This innovation can help patients win more treatment time, improve patient diagnosis and cure rates, and alleviate the pressure of medical staff shortage.

Influence of metabolic dysfunction-associated fatty liver disease on the prognosis of patients with HBV-related acute-on-chronic liver failure.

OBJECTIVES: Metabolic-associated fatty liver disease (MAFLD) has clinical relevance in patients with acute-on-chronic liver failure (ACLF). We investigated the association between MAFLD and prognosis in patients with ACLF. METHODS: We included patients with ACLF with available clinical data who visited our hospital for nearly 9 years. We compared the prognosis of patients in the different subgroups of ACLF and predicted the incidence of adverse outcomes. Moreover, a new model based on MAFLD was established. RESULTS: Among 339 participants, 75 had MAFLD. The prognosis of patients with ACLF was significantly correlated with MAFLD. Patients with ACLF with concomitant MAFLD tended to have a lower cumulative survival rate (p = 0.026) and a higher incidence of hepatorenal syndrome (9.33% versus 3.40%, p = 0.033) than those without MAFLD. We developed an TIM2 model and the area under the ROC curve of the new model for 30-day and 60-day mortality (0.759 and 0.748) was higher than other predictive methods. CONCLUSION: The presence of MAFLD in patients with HBV-related ACLF was associated with an increased risk of in-hospital mortality. Moreover, The TIM2 model is a high-performance prognostic score for HBV-related ACLF.