Bioconjugate Chemistry最新文献

{"title":"Lysosome-Targeted Naphthalimide-Based Fluorescence for the Detection of Fe(III) and Monitoring of Iron Metabolism.","authors":"Shuang-Shuang Long, Xi-Feng Zou, Wen-Xi Zhang, Ke Zeng, Qing-Long Qiao, Xu-Dong Jiang, Ying-Wu Lin","doi":"10.1021/acs.bioconjchem.5c00092","DOIUrl":"https://doi.org/10.1021/acs.bioconjchem.5c00092","url":null,"abstract":"<p><p>Iron is crucial for numerous biological processes, and lysosomes play an essential role in iron metabolism by regulating Fe³⁺ levels. Disruptions of this regulation can lead to Fe³⁺ accumulation, resulting in membrane damage and ferroptosis. Here, we have developed a water-soluble fluorescent probe <b>BiNIT</b> that specifically targets lysosomes for the selective detection of Fe³⁺. <b>BiNIT</b> features a bis-naphthalimide structure linked by a thiophene moiety and incorporates two quaternary ammonium groups, which enhance its ability to target lysosomes and its solubility in aqueous environments. The probe showed high selectivity for Fe³⁺, with fluorescence quenching resulting from the paramagnetism of Fe³⁺ and its capacity to induce probe aggregation. This aggregation occurs through coordination bonds between Fe³⁺ and the carbonyl oxygen, imide nitrogen, or thiophene sulfur in multiple probe molecules. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) confirmed the formation of nanoparticles upon Fe³⁺ binding. Moreover, <b>BiNIT</b> remains stable in environments with pH values above 4, facilitating precise monitoring of Fe³⁺ levels within lysosomes. This innovative tool provides valuable insights into iron homeostasis, oxidative stress, and ferroptosis, aiding research on iron-related diseases and the development of therapeutic strategies.</p>","PeriodicalId":29,"journal":{"name":"Bioconjugate Chemistry","volume":" ","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144273657","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"4′-C-Cholesterol/Pyridyl-2′-O-Methyl Uridine-Functionalized siRNA Enhances Stability and Carrier-Free Gene Silencing","authors":"Santanu Sar,&nbsp;Shalini Gupta,&nbsp;Gourav Das,&nbsp;Swrajit Nath Sharma,&nbsp;Deepak K,&nbsp;Atanu Ghosh,&nbsp;Siddharam Shivappa Bagale,&nbsp;Sumit Gangopadhyay,&nbsp;Surajit Sinha* and Kiran R. Gore*,&nbsp;","doi":"10.1021/acs.bioconjchem.5c0007910.1021/acs.bioconjchem.5c00079","DOIUrl":"https://doi.org/10.1021/acs.bioconjchem.5c00079https://doi.org/10.1021/acs.bioconjchem.5c00079","url":null,"abstract":"<p >Chemical modifications and targeted delivery through the conjugation of small molecules have transformed the potential of siRNA-based therapeutics. These advancements address key challenges, such as poor cellular uptake, low bioavailability, and limited metabolic stability, making siRNA delivery more efficient and clinically viable. Cholesterol-conjugated siRNA enables cellular uptake through lipoprotein pathways without transfection agents. In this study, we reported the synthesis of 4′-<i>C</i>-cholesterol-2′-<i>O</i>-methyl (4′-<i>C</i>-chol-2′-OMe) and 4′-<i>C</i>-methylpyridine-2′-<i>O</i>-methyl (4′-<i>C</i>-Mpy-2′-OMe) uridine conjugates via copper(I)-catalyzed azide–alkyne cycloaddition (CuAAC) and their incorporation at the 3′-overhangs of the siRNA duplex. A single incorporation of 4′-<i>C</i>-chol-2′-OMe or 4′-<i>C</i>-Mpy-2′-OMe uridine marginally increased the stability of the siRNA duplex. In the nuclease resistance assay, 4′-<i>C</i>-Mpy-2′-OMe modification at the penultimate position of the 3′-end of poly dT₂₀ showed significant resistance against snake venom phosphodiesterase (SVPD), 3′-specific exonucleases. Gene silencing activity using anti-<i>Renilla</i> siRNA exhibited enhanced gene silencing activity when a single modification was incorporated at the 3′-overhang of the passenger strand. Similarly, 4′-<i>C</i>-Mpy-2′-OMe modification at the 3′-overhang of the passenger strand in anti-<i>Bcl</i>-2 siRNA showed compatibility to RISC assembly and exhibited effective gene silencing against the endogenous <i>Bcl-2</i> gene. A molecular modeling study illustrated that the 4′-<i>C</i>-Mpy-2′-OMe uridine at the 3′-overhang of the guide strand shows minimal interaction with the PAZ domain of the hAgo2 protein. The dual incorporation of cholesterol modifications at the 3′-overhang of both strands resulted in 68% and 93% reductions in <i>Renilla</i> luciferase expression at 1000 nM concentration after 48 and 96 h, respectively, in a carrier-free system. This study demonstrated that C4′-cholesterol conjugation provides effective cellular uptake, high nuclease resistance, and prolonged silencing activity in carrier-free mode.</p>","PeriodicalId":29,"journal":{"name":"Bioconjugate Chemistry","volume":"36 6","pages":"1234–1246 1234–1246"},"PeriodicalIF":4.0,"publicationDate":"2025-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144306138","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multimeric Conjugates Using Engineered Peptide Scaffolds for Efficient siRNA Delivery","authors":"Quentin Vicentini,&nbsp;Dennis Hekman,&nbsp;Deepak Bhatt,&nbsp;Rouven Stulz,&nbsp;Mahya Dezfouli,&nbsp;Peter Gennemark,&nbsp;Nicola Guzzi,&nbsp;Naoko Toki,&nbsp;Bojana Lazovic,&nbsp;Carolina Tängemo,&nbsp;Shalini Andersson,&nbsp;Samir EL Andaloussi* and Anders Dahlén*,&nbsp;","doi":"10.1021/acs.bioconjchem.5c0015610.1021/acs.bioconjchem.5c00156","DOIUrl":"https://doi.org/10.1021/acs.bioconjchem.5c00156https://doi.org/10.1021/acs.bioconjchem.5c00156","url":null,"abstract":"<p >Oligonucleotide therapeutics (ONT) traditionally involve a single targeting moiety per oligonucleotide when conjugated for organ delivery. Multimerization represents a novel approach by connecting multiple ONTs to a single scaffold, thereby influencing the drug’s activity and biophysical properties <i>in vivo</i>. Recently, others have demonstrated the efficacy of this strategy, showing enhanced tissue retention and extended silencing with the capability to target multiple genes simultaneously. The investigation of diverse multimeric designs is thus an exciting opportunity to explore the delivery of the ONT. In this study, we engineered a versatile peptide branching unit able to link up to four small interfering RNAs together. We conjugated a GalNAc targeting moiety to these scaffolds for liver hepatocyte delivery and assessed their silencing activity. Our approach was further expanded to explore different peptide architectures (linear versus cyclized) and additional functionalities, including endosomal escape domains and dual target silencing. We then evaluated the constructs via subcutaneous and intravenous (i.v.) administration in mice. Notably, the intravenous administration of multimeric siRNA GalNAc demonstrated potent silencing in the liver and significantly affected liver-to-kidney biodistribution. Our findings suggest that peptides as branching units offer a promising pathway for ONT multimerization, advancing the challenges of drug delivery.</p>","PeriodicalId":29,"journal":{"name":"Bioconjugate Chemistry","volume":"36 6","pages":"1299–1310 1299–1310"},"PeriodicalIF":4.0,"publicationDate":"2025-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acs.bioconjchem.5c00156","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144305605","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multiprotein Silencing Using WRAP-Based Nanoparticles: A Proof of Concept","authors":"Karidia Konate,&nbsp;Irène Pezzati,&nbsp;Karima Redjatti,&nbsp;Estelle Agnel,&nbsp;Eric Vivès,&nbsp;Sandrine Faure,&nbsp;Pascal de Santa Barbara,&nbsp;Prisca Boisguérin* and Sébastien Deshayes*,&nbsp;","doi":"10.1021/acs.bioconjchem.5c0006910.1021/acs.bioconjchem.5c00069","DOIUrl":"https://doi.org/10.1021/acs.bioconjchem.5c00069https://doi.org/10.1021/acs.bioconjchem.5c00069","url":null,"abstract":"<p >Cancer remains the leading cause of death, with chemotherapy, radiotherapy, and surgical resection being the primary treatment methods. However, chemotherapy’s side effects, surgical limitations, and drug resistance present significant challenges. Small interfering RNA (siRNA) has emerged as a promising tool in cancer therapy due to its ability to silence disease-related genes selectively. Recent advancements in nonviral delivery systems, particularly cell-penetrating peptides (CPPs), have enhanced the efficacy of siRNA delivery. The use of siRNA as a therapeutic tool in cancer treatment has been reported in the literature. However, silencing only one target protein has only a minor effect on tumor cell proliferation, as previously shown for WRAP-based nanoparticles targeting cyclin-dependent kinase 4 (CDK4) in human U87 glioblastoma cells. Here, we designed a more sophisticated approach to enhance therapeutic efficacy, encapsulating multiple siRNAs targeting CDK4, cyclin D1 (CD1), and MCL-1 proteins. The siRNA cocktail, delivered via WRAP5 nanoparticles, effectively silenced these targets and reduced cell proliferation in human U87 glioblastoma cells. Furthermore, the nanoparticles also demonstrated potential therapeutic impact in gastrointestinal stromal tumors (GIST), a rare cancer characterized by its tendency to resist standard treatments. This study highlights the versatility of WRAP5 nanoparticles as a platform for personalized cancer therapy, suggesting that siRNA delivery systems may be tailored to specific cancer types for more effective treatment strategies.</p>","PeriodicalId":29,"journal":{"name":"Bioconjugate Chemistry","volume":"36 6","pages":"1218–1233 1218–1233"},"PeriodicalIF":4.0,"publicationDate":"2025-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144305591","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Light-Controllable PEG Hydrogel Cross-Linked by Reversibly Photodissociable Dimeric Green Fluorescent Protein pdDronpa for Drug Delivery","authors":"Yen Thi Nguyen,&nbsp;Hyuck Jin Lee* and Namdoo Kim*,&nbsp;","doi":"10.1021/acs.bioconjchem.5c0008810.1021/acs.bioconjchem.5c00088","DOIUrl":"https://doi.org/10.1021/acs.bioconjchem.5c00088https://doi.org/10.1021/acs.bioconjchem.5c00088","url":null,"abstract":"<p >Hydrogel has been widely studied as a carrier model system for drug delivery. Efficient encapsulation of drug molecules and their controlled release are important factors in the design of hydrogels to control drug release at a desired time and location. In this study, we propose a photoresponsive hydrogel with tunable mechanical properties for drug delivery. The hydrogel was synthesized by cross-linking maleimide-functionalized 4-armed polyethylene glycol (4-armed PEG-Mal) with reversibly photodissociable green fluorescent protein pdDronpa. Transitions in the physical state and/or mechanical strength of the hydrogel occurred rapidly when the cross-linking agent pdDronpa was switched off and on between the monomer and dimer states using 500 and 400 nm illumination, respectively. Optically controlled release of fluorescently labeled insulin was investigated, demonstrating the ability of this hydrogel as a potent drug delivery system.</p>","PeriodicalId":29,"journal":{"name":"Bioconjugate Chemistry","volume":"36 6","pages":"1247–1256 1247–1256"},"PeriodicalIF":4.0,"publicationDate":"2025-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144305604","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Developing and Characterizing the Tumor-Targeting Efficiency of an Anti-EphA2-CD11b Bispecific Antibody","authors":"Peggy A. Birikorang,&nbsp;Dominic M. Menendez,&nbsp;Robert Edinger,&nbsp;Gary Kohanbash* and W. Barry Edwards*,&nbsp;","doi":"10.1021/acs.bioconjchem.5c0007010.1021/acs.bioconjchem.5c00070","DOIUrl":"https://doi.org/10.1021/acs.bioconjchem.5c00070https://doi.org/10.1021/acs.bioconjchem.5c00070","url":null,"abstract":"<p >Targeting molecules, such as antibodies and peptides, play a key role in the precise delivery of cytotoxic payloads to tumor sites by binding to specific tumor-associated antigens or other proteins within the tumor microenvironment. This investigation evaluates the potential therapeutic application of a bispecific antibody (BsAb), which simultaneously targets EphA2, a tumor-associated antigen, and CD11b, a protein expressed by tumor-associated macrophages and myeloid-derived suppressor cells (TAMCs). Recombinantly produced anti-EphA2-CD11b-BsAb was conjugated to a bifunctional chelator, NOTA-SCN, and then radiolabeled with copper-64 (⁶⁴Cu). The [⁶⁴Cu]Cu-NOTA-anti-EphA2-CD11b-BsAb radioimmunoconjugate was subsequently administered to HT1080-fibrosarcoma-bearing nude mice via tail vein injection. Positron Emission Tomography (PET) and ex vivo biodistribution analyses were performed to determine tumor uptake and pharmacokinetic localization. At 4, 24, and 48 h postinjection (p.i.), the percent injected dose per gram (%ID/g) of [⁶⁴Cu]Cu-NOTA-anti-EphA2-CD11b-BsAb in HT1080 xenografts were 5.35 ± 2.24, 4.44 ± 1.90, and 4.10 ± 0.60, respectively. There was high uptake in the liver as well as in CD11b-expressing organs, including the spleen, bone marrow, and lung. Binding in these CD11b-rich organs was significantly reduced by coadministering the dose with nonradiolabeled anti-CD11b-IgG and anti-EphA2-CD11b-BsAb, with a concurrent increase in tumor uptake compared to nonblocked mice (8.39 ± 1.37%ID/g for blocked and 4.44 ± 1.90%ID/g for nonblocked at 24 h p.i., <i>p</i> = 0.0175). Further optimization studies showed that at lower molar activity (3.7 MBq/nmol, 100 μCi/nmol), there were significantly higher tumor accumulations and reduced uptake in CD11b-expressing organs compared to higher molar activity (22.2 MBq/nmol, 600 μCi/nmol). Anti-EphA2-CD11b-BsAb is a functional targeting molecule and would require optimization through molar activity or blocking with nonradiolabeled antibody to maximize tumor targeting.</p>","PeriodicalId":29,"journal":{"name":"Bioconjugate Chemistry","volume":"36 6","pages":"1208–1217 1208–1217"},"PeriodicalIF":4.0,"publicationDate":"2025-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144306118","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In Vivo Imaging of Pancreatic Cancer in BALB/c Mice Using Erlotinib-Conjugated Carbon Quantum Dots Derived from 1,4,5,8-Tetraminoanthraquinone","authors":"Susan Varghese,&nbsp;Merin K. Abraham,&nbsp;Geneva Indongo,&nbsp;Greeshma Rajeevan,&nbsp;Arathy B. K. Kala,&nbsp;Aishwarya Lekshman and Sony George*,&nbsp;","doi":"10.1021/acs.bioconjchem.5c0019110.1021/acs.bioconjchem.5c00191","DOIUrl":"https://doi.org/10.1021/acs.bioconjchem.5c00191https://doi.org/10.1021/acs.bioconjchem.5c00191","url":null,"abstract":"<p >Pancreatic cancer remains one of the most aggressive malignancies with a poor prognosis due to late-stage diagnosis and limited treatment options. Fluorescence imaging has emerged as a valuable tool for early detection and targeted imaging of pancreatic cancer, offering improved visualization of tumors at the molecular level. Among various fluorescence techniques, fluorescence imaging using longer-wavelength nanomaterials holds significant promise due to their deeper tissue penetration and reduced background autofluorescence. In this study, we report the development of red-emitting carbon quantum dots designed for targeted imaging of pancreatic cancer. These carbon quantum dots were functionalized with erlotinib to enhance cancer cell specificity. In vitro biological evaluations demonstrated minimal cytotoxicity, prompting further investigations in vivo. Using BALB/c mice as model organisms, in vivo imaging showcased the efficacy of the developed probe for targeted pancreatic cancer detection, suggesting its potential as a robust tool for cancer diagnostics and imaging.</p>","PeriodicalId":29,"journal":{"name":"Bioconjugate Chemistry","volume":"36 6","pages":"1329–1339 1329–1339"},"PeriodicalIF":4.0,"publicationDate":"2025-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144306025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Genetic Engineering of VHH Antibody Fragments for Efficient Site-Specific Conjugation to Polysaccharides","authors":"Lin Zhong,&nbsp;Lisanne C. M. Morshuis,&nbsp;Michelle Koerselman,&nbsp;Angela Memelink,&nbsp;Anna Kolecka,&nbsp;Raimond Heukers,&nbsp;Theo Verrips,&nbsp;Marcel Karperien* and Bram Zoetebier*,&nbsp;","doi":"10.1021/acs.bioconjchem.5c0016710.1021/acs.bioconjchem.5c00167","DOIUrl":"https://doi.org/10.1021/acs.bioconjchem.5c00167https://doi.org/10.1021/acs.bioconjchem.5c00167","url":null,"abstract":"<p >Site-selective modifications of proteins, without compromising their biological activity, are highly sought after due to their critical role in many biomedical applications. Here, we established a universal and efficient approach for site-selective conjugation of a variable domain of single-chain heavy-chain only antibody fragments (VHH) to polysaccharides using thiol–maleimide chemistry, known for its specificity and efficiency. This is achieved by genetically engineering an unpaired cysteine (Cys) residue in a C-terminal extension of VHHs. In this study, we synthesized two maleimide-functionalized polysaccharides, i.e., dextran-maleimide (Dex-Mal) and hyaluronic acid-maleimide (HA-Mal), for protein conjugation. Six distinct VHHs were selected and engineered with C-terminal extensions containing Cys residues for conjugation with Dex-Mal and HA-Mal. Conjugation efficiency varied among VHHs due to structural heterogeneity, which influenced the reactivity of the engineered Cys residues. One VHH, specific to TNFα (anti-TNFα-VHH), exhibited low conjugation efficiency (&lt;20%); however, efficiency was fully restored when a flexible glycine-serine G₄S linker was introduced between the variable domain and the C-terminal Cys tag. Additionally, incorporation of two free Cys residues in the C-terminal tail further enhanced conjugation efficiency. This work establishes a robust and versatile approach for generating protein–polysaccharide conjugates, paving the way for therapeutic and diagnostic applications.</p>","PeriodicalId":29,"journal":{"name":"Bioconjugate Chemistry","volume":"36 6","pages":"1319–1328 1319–1328"},"PeriodicalIF":4.0,"publicationDate":"2025-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acs.bioconjchem.5c00167","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144305913","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Targeting HER2 with DNA Aptamers for Efficient Anticancer Drug Delivery: A Combined Experimental and Computational Study","authors":"Konstantin E. Katsuba,&nbsp;Lidia M. Zabegina,&nbsp;Daniil S. Plevako,&nbsp;Andrey A. Gurtovenko and Anastasia V. Malek*,&nbsp;","doi":"10.1021/acs.bioconjchem.5c0002210.1021/acs.bioconjchem.5c00022","DOIUrl":"https://doi.org/10.1021/acs.bioconjchem.5c00022https://doi.org/10.1021/acs.bioconjchem.5c00022","url":null,"abstract":"<p >Targeted delivery of cytostatic drugs is a powerful approach to achieving tumor tissue selectivity, reducing systemic toxicity, and ultimately improving the efficacy of anticancer chemotherapy. Targeting can be achieved using a wide range of molecular ligands, with DNA aptamers being a promising representative. In this work, we employed flow cytometry, a AuNP-aptasensor, and atomic-scale computer modeling to assess the affinity of several DNA aptamers (Anti-HER2, HB5, Apt-6, HeA2_1, and HeA2_3) for human epidermal growth factor receptor 2 (HER2), which is known to be one of the factors that promote the growth of breast cancer cells. Flow cytometry showed that short aptamers (HeA2_1 and HeA2_3) had a higher affinity for HER2 on MDAMB453 cancer cells than longer aptamers (HB5, Apt-6). HER2-negative MDA-MB-231 cells served as the negative control. The HeA2_3 aptamer has a high average affinity (HeA2_3:23.6, HeA2_1:13.1, Apt-6:3.6; HB5:3.5; Anti-HER2:3.2) and a nearly Gaussian distribution across the cells, while HeA2_1 forms a fraction of cells with a relatively high fluorescence signal intensity (HeA2_1:11.6; HeA2_3:5.9; Apt-6:3.4; HB5:3.1; Anti-HER2:2.1). Most of the findings for cancer cells also hold for the HER2-positive small extracellular vesicles studied using the AuNP-aptasensor. Computer simulations confirmed that short aptamers are characterized by stronger binding to the extracellular domain of HER2. A detailed analysis of the free energy allowed us to show for the first time that tight binding to HER2 correlates with well-separated hot and cold spots on the protein surface. For the aptamers that meet these criteria (HeA2_1, HeA2_3, and Anti-HER2), favorable interactions with HER2 are driven by the local attraction of nucleotides to arginine and lysine residues of HER2 and possibly stabilized by intermolecular hydrogen bonds. For longer aptamers (Apt-6 and HB5), hot and cold spots on the HER2 surface overlap and the aptamers show much weaker binding. Overall, our findings show that binding of DNA aptamers to HER2 cannot be characterized merely by the dissociation equilibrium constant. A more sophisticated approach that combines experimental and computational methods allowed us to unlock the molecular mechanisms behind the aptamer–HER2 bindings. The results of our study also suggest that computer modeling has become a reliable and accurate tool for aptamer prescreening prior to laboratory experiments.</p>","PeriodicalId":29,"journal":{"name":"Bioconjugate Chemistry","volume":"36 6","pages":"1180–1196 1180–1196"},"PeriodicalIF":4.0,"publicationDate":"2025-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144305901","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Facially Amphiphilic Cholate-Conjugated Polymers for Regulating Insulin Fibrillation.","authors":"Desoshree Ghosh, Sagar Bag, Priyadarsi De","doi":"10.1021/acs.bioconjchem.5c00097","DOIUrl":"10.1021/acs.bioconjchem.5c00097","url":null,"abstract":"<p><p>To understand the influence of facially amphiphilic polymers (FAPs) on insulin fibril (IF) inhibition, three different cholate-based FAPs [cationic (<b>PFCAQA</b>), anionic (<b>PFCASF</b>), and zwitterionic (<b>PFCASB</b>)] have been synthesized. Besides, two control polymers [cholate and sulfobetaine-pendant random copolymer <b>PRCASB</b> (without facial amphiphilicity) and sulfobetaine-tethered homopolymer <b>PSBMA</b> (without cholate pendants)] are also prepared. Several biophysical experiments such as spectroscopic techniques [thioflavin T (ThT), Nile red (NR), tyrosine (Tyr) fluorescence assay], turbidity assay by ultraviolet-visible (UV-vis) spectroscopy, dynamic light scattering (DLS), circular dichroism (CD) study, and microscopic investigation are performed to investigate the role of polymers as antiamyloidogenic agents during insulin fibrillation. Interestingly, the <b>PFCASB</b> zwitterionic polymer behaves as the most efficacious antiamyloidogenic agent. To clarify the interaction of <b>PFCASB</b> and native insulin (NI), an isothermal titration calorimetry (ITC) experiment is carried out. Tyr and the NR fluorescence investigation suggest the important role of hydrophobic interactions, whereas the ITC experiment confirms the significance of hydrophobic and electrostatic interactions in the IF inhibitory process. A hemolytic test is conducted to investigate the toxicity caused by IF and the efficacy of <b>PFCASB</b> in prohibiting erythrocyte disruption caused by IF. Overall, the present work reveals the impact of the facially amphiphilic cholic acid (CA)-based zwitterionic polymer in modulating the insulin aggregation process and gives a new perspective for investigations on different protein aggregations.</p>","PeriodicalId":29,"journal":{"name":"Bioconjugate Chemistry","volume":" ","pages":"1040-1053"},"PeriodicalIF":4.0,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143952257","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}