Characterization of an α-L-fucosidase in marine bacterium Wenyingzhuangia fucanilytica: new evidence on the catalytic sites of GH95 family glycosidases.

BACKGROUND: α-l-Fucose confers unique functions for fucose-containing biomolecules such as human milk oligosaccharides. α-l-Fucosidases can serve as desirable tools in the application of fucosylated saccharides. Discovering novel α-l-fucosidases and elucidating their enzyme properties are always worthy tasks. RESULTS: A GH95 family α-l-fucosidase named Afc95A_Wf was cloned from the genome of the marine bacterium Wenyingzhuangia fucanilytica and expressed in Escherichia coli. It exhibited maximum activity at 40 °C and pH 7.5. Afc95A_Wf defined a different substrate specificity among reported α-l-fucosidases, which was capable of hydrolyzing α-fucoside in CNP-fucose, Fucα1-2Galß1-4Glc and Galß1-4(Fucα1-3)Glc, and showed a preference for α1,2-fucosidic linkage. It adopted Asp residue in the amino acid sequence at position 391, which was distinct from the previously acknowledged residue of Asn. The predicted tertiary structure and site-directed mutagenesis revealed that Asp391 participates in the catalysis of Afc95A_Wf. The differences in the substrate specificity and catalytic site shed light on that Afc95A_Wf adopted a novel mechanism in catalysis. CONCLUSION: A GH95 family α-l-fucosidase (Afc95A_Wf) was cloned and expressed. It showed a cleavage preference for α1,2-fucosidic linkage to α1,3-fucosidic linkage. Afc95A_Wf demonstrated a different substrate specificity and a residue at an important catalytic site compared with known GH95 family proteins, which revealed the occurrence of diversity on catalytic mechanisms in the GH95 family. © 2024 Society of Chemical Industry.

Research progress on the nonstructural protein 1 (NS1) of influenza a virus.

Influenza A virus (IAV) is the leading cause of highly contagious respiratory infections, which poses a serious threat to public health. The non-structural protein 1 (NS1) is encoded by segment 8 of IAV genome and is expressed in high levels in host cells upon IAV infection. It is the determinant of virulence and has multiple functions by targeting type Ι interferon (IFN-I) and type III interferon (IFN-III) production, disrupting cell apoptosis and autophagy in IAV-infected cells, and regulating the host fitness of influenza viruses. This review will summarize the current research on the NS1 including the structure and related biological functions of the NS1 as well as the interaction between the NS1 and host cells. It is hoped that this will provide some scientific basis for the prevention and control of the influenza virus.

Virtual Screening, Molecular Dynamics Simulation, and Bioactivity Assessment Validate T13074 as a Dual-Target EGFR/c-Met Inhibitor.

OBJECTIVES: The objective of this study is to identify dual-target inhibitors against EGFR/c-Met through virtual screening, dynamic simulation, and biological activity evaluation. This endeavor is aimed at overcoming the challenge of drug resistance induced by L858R/T790M mutants. METHODS: Active structures were gathered to construct sets of drug molecules. Next, property filtering was applied to the drug structures within the compound library. Active compounds were then identified through virtual screening and cluster analysis. Subsequently, we conducted MTT antitumor activity evaluation and kinase inhibition assays for the active compounds to identify the most promising candidates. Furthermore, AO staining and JC-1 assays were performed on the selected compounds. Ultimately, the preferred compounds underwent molecular docking and molecular dynamics simulation with the EGFR and c-Met proteins, respectively. RESULT: The IC50 of T13074 was determined as 2.446 µM for EGFRL858R/T790M kinase and 7.401 nM for c-Met kinase, underscoring its potential in overcoming EGFRL858R/T790M resistance. Additionally, T13074 exhibited an IC50 of 1.93 µM on the H1975 cell. Results from AO staining and JC-1 assays indicated that T13074 induced tumor cell apoptosis in a concentration-dependent manner. Notably, the binding energy between T13074 and EGFR protein was found to be -90.329 ± 16.680 kJ/mol, while the binding energy with c-Met protein was -139.935 ± 17.414 kJ/mol. CONCLUSION: T13074 exhibited outstanding antitumor activity both in vivo and in vitro, indicating its potential utility as a dual-target EGFR/c-Met inhibitor. This suggests its promising role in overcoming EGFR resistance induced by the L858R/T790M mutation.

Associations between CDH1 gene polymorphisms and the risk of gastric cancer: A meta-analysis based on 44 studies.

BACKGROUND: Numerous studies have investigated the association between CDH1 polymorphisms and gastric cancer (GC) risk. However, the results have been inconsistent and controversial. To further determine whether CDH1 polymorphisms increase the risk of GC, we conducted a meta-analysis by pooling the data. METHODS: Relevant case-control studies were collected from PubMed, Embase, Web of Science and Cochrane databases up to January 7, 2024. Subsequently, odds ratios (ORs) with 95% confidence intervals (CIs) were used to evaluate the strength of correlations. A sensitivity analysis was performed to evaluate the robustness and reliability of these included studies. RESULTS: A total of 25 articles including 44 studies, were included in this meta-analysis, including 26 studies on rs16260, 6 studies on rs3743674, 7 studies on rs5030625, and 5 studies on rs1801552. The pooled results showed that rs16260 was remarkably associated with an increased GC risk of GC among Caucasians. Moreover, the rs5030625 variation dramatically enhanced GC predisposition in the Asian population. However, no evident correlations between CDH1 rs3743674 and rs1801552 polymorphisms and GC risk were observed. CONCLUSIONS: Our findings suggested that CDH1 gene polymorphisms were significantly correlated with GC risk, especially in rs16260 and rs5030625 polymorphisms.

Superimposed Electric Field Enhanced Electrospray for High-Throughput and Consistent Cell Encapsulation.

Cell encapsulation technology, crucial for advanced biomedical applications, faces challenges in existing microfluidic and electrospray methods. Microfluidic techniques, while precise, can damage vulnerable cells, and conventional electrospray methods often encounter instability and capsule breakage during high-throughput encapsulation. Inspired by the transformation of the working state from unstable dripping to stable jetting triggered by local electric potential, this study introduces a superimposed electric field (SEF)-enhanced electrospray method for cell encapsulation, with improved stability and biocompatibility. Utilizing stiffness theory, we quantitatively analyze the stability of the electrospray, whose stiffness is five times stronger under conical confinement. The SEF technique enabled rapid, continuous production of ∼300 core-shell capsules per second in an aqueous environment, significantly improving cell encapsulation efficiency. Our method demonstrated remarkable potential as exemplified in two key applications: 1) a 92-fold increase in human-derived induced pluripotent stem cells (iPSCs) expansion over 10 days, outperforming traditional 2D cultures in both growth rate and pluripotency maintenance, and 2) the development of liver capsules for steatosis modeling, exhibiting normal function and biomimetic lipid accumulation. The SEF-enhanced electrospray method presents a significant advancement in cell encapsulation technology. It offers a more efficient, stable, and biocompatible approach, opening new possibilities in clinical transplantation, drug screening, and cell therapy. This article is protected by copyright. All rights reserved.

iSERS: from nanotag design to protein assays and ex vivo imaging.

Proteins are an eminently important class of ubiquitous biomacromolecules with diverse biological functions, and numerous techniques for their detection, quantification, and localisation have been developed. Many of these methods exploit the selectivity arising from molecular recognition of proteins/antigens by immunoglobulins. The combination of surface-enhanced Raman scattering (SERS) with such "immuno"-techniques to immuno-SERS (iSERS) is the central topic of this review, which is focused on colloidal SERS nanotags, i.e., molecularly functionalised noble metal nanoparticles conjugated to antibodies, for their use in protein assays and ex vivo imaging. After contrasting the fundamental differences between label-free SERS and iSERS, including a balanced description of the advantages and drawbacks of the latter, we describe the usual workflow of iSERS experiments. Milestones in the development of the iSERS technology are summarised from a historical perspective. By highlighting selected examples from the literature, we illustrate the conceptual progress that has been achieved in the fields of iSERS-based protein assays and ex vivo imaging. Finally, we attempt to predict what is necessary to fully exploit the transformative potential of the iSERS technology by stimulating the transition from research in academic labs into applications for the benefit of our society.

Clinical outcomes of radiofrequency ablation using a radiofrequency needle device for varicose ulcer: A non-randomized controlled prospective study.

OBJECTIVE: To evaluate the short-term clinical outcomes of radiofrequency ablation (RFA) using a radiofrequency (RF) needle device for varicose ulcers. METHODS: From September 2020 to September 2021, a total of 80 patients with varicose ulcers were included in this study. Based on the different surgical methods, the patients were divided into RF group and control groups, with 40 cases in each group. In the RF group, RFA was performed using an RF needle device and foam sclerotherapy was used for superficial veins. The control group was treated with conventional high-ligation stripping. The surgical data, hospitalization data, clinical efficacy, and postoperative complications of two groups were compared. Meanwhile, the correlation between RBC, HB, HCT, and ulcer healing time was analyzed. RESULTS: Compared to the control group, RF group had shorter surgery time, duration in the hospital, and less intraoperative bleeding (p < .05). The VCSS and CIVIQ scores in RF group were significantly higher than that in control group (p < .05). The healing time of ulcers was shorter in the RF group (x2 = 19.766, p = .000). The RF group had fewer postoperative complications. There was a positive correlation between RBC, HB, and HCT, and ulcer healing time (p < .05). CONCLUSION: The use of the RF needle device for RFA to treat patients with varicose ulcers showed acceptable short-term clinical outcomes with less incidence of trauma, faster recovery, and fewer complications.

Role of inflammatory cytokine in mediating the effect of plasma lipidome on epilepsy: a mediation Mendelian randomization study.

Background: Epilepsy is one of the most prevalent serious brain disorders globally, impacting over 70 million individuals. Observational studies have increasingly recognized the impact of plasma lipidome on epilepsy. However, establishing a direct causal link between plasma lipidome and epilepsy remains elusive due to inherent confounders and the complexities of reverse causality. This study aims to investigate the causal relationship between specific plasma lipidome and epilepsy, along with their intermediary mediators. Methods: We conducted a two-sample Mendelian randomization (MR) and mediation MR analysis to evaluate the causal effects of 179 plasma lipidomes and epilepsy, with a focus on the inflammatory cytokine as a potential mediator based on the genome-wide association study. The primary methodological approach utilized inverse variance weighting, complemented by a range of other estimators. A set of sensitivity analyses, including Cochran's Q test, I 2 statistics, MR-Egger intercept test, MR-PRESSO global test and leave-one-out sensitivity analyses was performed to assess the robustness, heterogeneity and horizontal pleiotropy of results. Results: Our findings revealed a positive correlation between Phosphatidylcholine (18:1_18:1) levels with epilepsy risk (OR = 1.105, 95% CI: 1.036-1.178, p = 0.002). Notably, our mediation MR results propose Tumor necrosis factor ligand superfamily member 12 levels (TNFSF12) as a mediator of the relationship between Phosphatidylcholine (18,1_18:1) levels and epilepsy risk, explaining a mediation proportion of 4.58% [mediation effect: (b = 0.00455, 95% CI: -0.00120-0.01030), Z = 1.552]. Conclusion: Our research confirms a genetic causal relationship between Phosphatidylcholine (18:1_18:1) levels and epilepsy, emphasizing the potential mediating role of TNFSF12 and provide valuable insights for future clinical investigations into epilepsy.

A comprehensive review of sulfated fucan from sea cucumber: Antecedent and prospect.

Sulfated fucan from sea cucumber is mainly consists of L-fucose and sulfate groups. Recent studies have confirmed that the structure of sulfated fucan mainly consists of repeating units, typically tetrasaccharides. However, there is growing evidence indicating the presence of irregular domains with heterogeneous units that have not been extensively explored. Moreover, as a key contributor to the nutritional benefits of sea cucumbers, sulfated fucan demonstrates a range of biological activities, such as anti-inflammatory, anticancer, hypolipidemic, anti-hyperglycemic, antioxidant, and anticoagulant properties. These biological activities are profoundly influenced by the structural features of sulfated fucan including molecular weight and distribution patterns of sulfate groups. The latest research indicates that sulfated fucan is dispersed in the extracellular matrix of the body wall of sea cucumbers. This article aimed to review the research progress on the in-situ distribution, structures, structural elucidation strategies, functions, and structure-activity relationships of sulfated fucan, especially in the last decade. It also provided insights into the major challenges and potential solutions in the research and development of sulfated fucan. Moreover, the fucanase and carbohydrate binding modules are anticipated to play pivotal roles in advancing this field.

Design, Synthesis, and Biological Evaluation of Chroman Derivatives as PD-1/PD-L1 Antagonists.

Programmed death-ligand 1 (PD-L1) has emerged as a promising therapeutic target for various cancers due to its crucial role in promoting tumor immune evasion. Here, we report a novel class of chroman-like small-molecule PD-L1 inhibitors exhibiting significant activity in inhibiting the PD-1/PD-L1 interaction. Employing a "ring-close" strategy for conformational restriction, we have achieved compound C27, which demonstrates superior PD-1/PD-L1 inhibitory activity compared to the positive control. Molecular dynamics simulation and binding free energy calculation predict that (R)-C27 with inhibitory activity surpassed (S)-C27. The experimental results from bioassay and X-ray structural analysis corroborate these findings. All these results collectively indicate that (R)-C27 is a promising lead compound deserving further exploration.

Effects of myo-inositol on regulating glucose and lipid metabolism and alternative splicing events coexpressed with lncRNAs in the liver tissues of diabetic mice.

Objective: Recent studies have shown that gene alternative splicing (AS) and long noncoding RNAs (lncRNAs) are involved in diabetes mellitus (DM) and its complications. Currently, myo-inositol (MI) is considered as effective for the treatment of insulin resistance and lipid metabolism disorders in diabetes patients. We hope to better explore the potential roles of gene AS and lncRNAs in liver glucose and lipid metabolism in diabetes, as well as the effects of myo-inositol treatment, through transcriptome analysis. Methods: This study analysed glucose and lipid metabolism-related biochemical indicators and liver HE staining in four groups of mice: the control group (Ctrl group), the diabetes group (DM group), the myo-inositol treatment group (MI group), and the metformin treatment group (Met group). The changes in relevant gene-regulated alternative splicing events (RASEs) and lncRNAs were analysed by RNA sequencing of liver tissue, and coexpression analysis and functional enrichment analysis were used to predict the possible lncRNAs and RASEs involved in liver glucose and lipid metabolism. Result: Metformin and myo-inositol alleviated insulin resistance, lipid metabolism disorders, and hepatic steatosis in diabetic mice. Transcriptome sequencing analysis revealed differential splicing events of genes related to lipid metabolism and differentially expressed lncRNAs (DElncRNAs). Six different lncRNAs and their potentially interacting splicing events were predicted. Conclusion: The present study revealed novel changes in RASEs and lncRNAs in the livers of diabetic mice following treatment with myo-inositol, which may shed light on the potential mechanisms by which myo-inositol delays and treats the progression of hepatic glucose and lipid metabolism in diabetes.

ADCY3: the pivotal gene in classical ketogenic diet for the treatment of epilepsy.

Objective: Epilepsy is a common neurological disorder characterized by recurrent epilepsy episodes. As a non-pharmacological treatment, the ketogenic diet has been widely applied in treating epilepsy. However, the exact therapeutic mechanism of the ketogenic diet for epilepsy remains unclear. This study investigates the molecular mechanisms of the ketogenic diet in regulating fatty acid metabolism and activating the ADCY3-initiated cAMP signaling pathway to enhance neuronal inhibition and thereby treat epilepsy. Methods and results: Meta-analysis reveals that the ketogenic diet is superior to the conventional diet in treating epilepsy. Animal experiments demonstrate that the ketogenic diet is more effective than the conventional diet in treating epilepsy, with the best results achieved using the classic ketogenic diet. Transcriptome sequencing analysis identifies six essential genes, among which ADCY3 shows increased expression in the ketogenic diet. In vivo experiments confirm that the activation of the cAMP-PKA signaling pathway by ADCY3 enhances neuronal inhibition and improves epilepsy control. Conclusion: Clinical observations indicate that the ketogenic diet improves patient epilepsy episodes by regulating the ADCY3-initiated cAMP signaling pathway.

Structural impacts on the degradation behaviors of Ir-based electrocatalysts during water oxidation in acid.

Large-scale hydrogen production by electrocatalytic water splitting still remains as a critical challenge due to the severe catalyst degradation during the oxygen evolution reaction (OER) in acidic media. In this study, we investigate the structural impacts on catalyst degradation behaviors using three iridium-based oxides, namely SrIrO3, Sr2IrO4, and Sr4IrO6 as model catalysts. These Ir oxides possess different connection configurations of [IrO6] octahedra units in their structure. Stable OER performance is observed on SrIrO3 and attributed to the edge-linked [IrO6] structure and rapid formation of a continuous IrOx layer on its surface, which functions not only as the "real" catalyst but also a shield preventing continuous cation leaching (with <1.0 at.% of Ir leaching). In comparison, both Sr2IrO4 and Sr4IrO6 catalysts demonstrate quick current fading with structure transformation to rutile IrO2 and formation of inconducive SrSO4 precipitates on surface, blocking the reactive sites. Nevertheless, over 60 at.% of Ir leaching is detected from the Sr4IrO6 catalyst due to its isolated [IrO6] structure configuration. Results of this work highlight the structural impacts on the catalyst stability in acidic OER conditions.

Restoring BARX2 in OSCC reverses partial EMT and suppresses metastasis through miR-186-5p/miR-378a-3p-dependent SERPINE2 inhibition.

Tumor cells undergoing partial epithelial-mesenchymal transition (pEMT) are pivotal in local invasion and lymphatic metastasis of oral squamous cell carcinoma (OSCC), yet the mechanisms behind pEMT reversal remain poorly understood. In this study, the loss of BARX2 expression was revealed during the process of oral epithelial carcinogenesis and identified to activate the pEMT program, facilitate metastasis, and be associated with poor prognosis. Restoring BARX2 expression in OSCC cell lines effectively reversed tumor pEMT, evident in E/N-Cadherin switching, reduced cell invasion, proliferation, and stemness, and inhibited murine lung metastasis. BARX2 re-expression negatively correlated with several pEMT markers, notably SERPINE2, which was enriched in the invasive OSCC front, enhancing stemness and promoting metastasis, particularly in cervical lymph nodes. Furthermore, rescuing SERPINE2 impaired the inhibitory effect of BARX2 on the pEMT programs and reconstructed ECM through re-expression of MMP1. Mechanistically, we identified that BARX2 inhibited SERPINE2 through activating miR-186-5p and miR-378a-3p. These miRNAs, upregulated by BARX2, post-transcriptionally degraded SERPINE2 mRNA via targeting specific sequences. Blocking miR-186-5p and miR-378a-3p effectively abolished the negative regulatory effect of BARX2 on SERPINE2. Overall, our findings highlight BARX2 as a partial EMT-reverser in OSCC, providing fresh therapeutic prospects for restoring BARX2 signaling to inhibit invasion and metastasis.

Circular RNA circHIPK2 inhibits colon cancer cells through miR-373-3p/RGMA axis.

Circular RNAs (circRNAs) have been implicated in cancer development. However, their regulation, function, and underlying mechanisms of action remain unclear. We found that circHIPK2 was downregulated in colon cancer, and low expression levels of circHIPK2 were associated with high tumor grade and poor patient survival. The expression of circHIPK2 was observed to be regulated by the transcription factor HOXD10, which was downregulated in colon cancer. Consequently, low circHIPK2 expression promoted colon cancer cell proliferation, migration, and invasion in vitro and tumor growth and metastasis in vivo. Mechanistically, circHIPK2 sponges miR-373-3p to upregulate the expression of the tumor suppressor RGMA, leading to the activation of BMP/Smad signaling and, ultimately, the inhibition of colon cancer cells, indicating that circHIPK2 inhibits colon cancer cells through the miR-373-3p/RGMA/BMP pathway. These findings revealed a previously unknown regulation, function, and underlying mechanism of circHIPK2 in cancer cells. Hence, circHIPK2 may have a prognostic value and serve as a potential target for colon cancer treatment.

The α-linkage in funoran and agarose could be hydrolyzed by a GH96 family enzyme: Discovery of the α-funoranase.

Agarans represent a group of galactans extracted from red algae. Funoran and agarose are the two major types and commercially applied polysaccharides of agaran. Although the glycoside hydrolases targeting ß-glycosidic bonds of agaran have been widely investigated, those capable of degrading α-glycosidic bonds of agarose were limited, and the enzyme degrading α-linkages of funoran has not been reported till now. In this study, a GH96 family enzyme BiAF96A_Aq from a marine bacterium Aquimarina sp. AD1 was heterologously expressed in Escherichia coli. BiAF96A_Aq exhibited dual activities towards the characteristic structure of funoran and agarose, underscoring the multifunctionality of GH96 family members. Glycomics and NMR analysis revealed that BiAF96A_Aq hydrolyzed the α-1,3 glycosidic bonds between 3,6-anhydro-α-l-galactopyranose (LA) and ß-d-galactopyranose-6-sulfate (G6S) of funoran, as well as LA and ß-d-galactopyranose (G) of agarose, through an endo-acting manner. The end products of BiAF96A_Aq were majorly composed of disaccharides and tetrasaccharides. The identification of the activity of BiAF96A_Aq on funoran indicated the first discovery of the funoran hydrolase for α-1,3 linkage. Considering the novel catalytic reaction, we proposed to name this activity as "α-funoranase" and recommended the assignment of a dedicated EC number for its classification.

Identification and characterization of a chondroitinase ABC with a novel carbohydrate-binding module.

Chondroitinases play important roles in structural and functional studies of chondroitin sulfates. Carbohydrate-binding module (CBM) is generally considered as an accessory module in carbohydrate-active enzymes, which promotes the association of the appended enzyme with the substrate and potentiates the catalytic activity. However, the role of natural CBM in chondroitinases has not been investigated. Herein, a novel chondroitinase ChABC29So containing an unknown domain with a predicted ß-sandwich fold was discovered from Segatella oris. Recombinant ChABC29So showed enzyme activity towards chondroitin sulfates and hyaluronic acid and acted in a random endo-acting manner. The unknown domain exhibited a chondroitin sulfate-binding capacity and was identified as a CBM. Biochemical characterization of ChABC29So and the CBM-truncated enzyme revealed that the CBM enhances the catalytic activity, thermostability, and disaccharide proportion in the final enzymatic products of ChABC29So. These findings demonstrate the role of the natural CBM in a chondroitinase and will guide future modification of chondroitinases.

Structural investigation of Fun168A unraveling the recognition mechanism of endo-1,3-fucanase towards sulfated fucan.

BACKGROUND: Sulfated fucan has gained interest due to its various physiological activities. Endo-1,3-fucanases are valuable tools for investigating the structure and establishing structure-activity relationships of sulfated fucan. However, the substrate recognition mechanism of endo-1,3-fucanases towards sulfated fucan remains unclear, limiting the application of endo-1,3-fucanases in sulfated fucan research. SCOPE AND APPROACH: This study presented the first crystal structure of endo-1,3-fucanase (Fun168A) and its complex with the tetrasaccharide product, utilizing X-ray diffraction techniques. The novel subsite specificity of Fun168A was identified through glycomics and nuclear magnetic resonance (NMR). KEY FINDINGS AND CONCLUSIONS: The structure of Fun168A was determined at 1.92 Å. Residues D206 and E264 acted as the nucleophile and general acid/base, respectively. Notably, Fun168A strategically positioned a series of polar residues at the subsites ranging from -2 to +3, enabling interactions with the sulfate groups of sulfated fucan through salt bridges or hydrogen bonds. Based on the structure of Fun168A and its substrate recognition mechanisms, the novel subsite specificities at the -2 and +2 subsites of Fun168A were identified. Overall, this study provided insight into the structure and substrate recognition mechanism of endo-1,3-fucanase for the first time and offered a valuable tool for further research and development of sulfated fucan.

Characterization and Structural Analysis of a Novel Carbohydrate-Binding Module from Family 96 with Chondroitin Sulfate-Specific Binding Capacity.

Chondroitin sulfate (CS) is the predominant glycosaminoglycan within the human body and is widely applied in various industries. Carbohydrate-binding modules (CBMs) possessing the capacity for carbohydrate recognition are verified to be important tools for polysaccharide investigation. Only one CS-specific CBM, PhCBM100, has hitherto been characterized. In the present study, two CBM96 domains present in the same putative PL8_3 chondroitin AC lyase were discovered and recombinantly expressed. The results of microtiter plate assays and affinity gel electrophoresis assays showed that the two corresponding proteins, DmCBM96-1 and DmCBM96-2, bind specifically to CSs. The crystal structure of DmCBM96-1 was determined at a 2.20 Å resolution. It adopts a ß-sandwich fold comprising two antiparallel ß-sheets, showing structural similarities to TM6-N4, which is the founding member of the CBM96 family. Site mutagenesis analysis revealed that the residues of Arg27, Lys45, Tyr51, Arg53, and Arg157 are critical for CS binding. The characterization of the two CBM96 proteins demonstrates the diverse ligand specificity of the CBM96 family and provides promising tools for CS investigation.