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Lefèbre J, Falk T, Ning Y, Rademacher C. Secondary Sites of the C-type Lectin-Like Fold. Chemistry 2024; 30:e202400660. [PMID: 38527187 DOI: 10.1002/chem.202400660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2024] [Revised: 03/23/2024] [Accepted: 03/25/2024] [Indexed: 03/27/2024]
Abstract
C-type lectins are a large superfamily of proteins involved in a multitude of biological processes. In particular, their involvement in immunity and homeostasis has rendered them attractive targets for diverse therapeutic interventions. They share a characteristic C-type lectin-like domain whose adaptability enables them to bind a broad spectrum of ligands beyond the originally defined canonical Ca2+-dependent carbohydrate binding. Together with variable domain architecture and high-level conformational plasticity, this enables C-type lectins to meet diverse functional demands. Secondary sites provide another layer of regulation and are often intricately linked to functional diversity. Located remote from the canonical primary binding site, secondary sites can accommodate ligands with other physicochemical properties and alter protein dynamics, thus enhancing selectivity and enabling fine-tuning of the biological response. In this review, we outline the structural determinants allowing C-type lectins to perform a large variety of tasks and to accommodate the ligands associated with it. Using the six well-characterized Ca2+-dependent and Ca2+-independent C-type lectin receptors DC-SIGN, langerin, MGL, dectin-1, CLEC-2 and NKG2D as examples, we focus on the characteristics of non-canonical interactions and secondary sites and their potential use in drug discovery endeavors.
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Affiliation(s)
- Jonathan Lefèbre
- Department of Pharmaceutical Sciences, University of Vienna, Vienna, Austria
- Vienna Doctoral School of Pharmaceutical, Nutritional and Sport, Sciences, University of Vienna, Vienna, Austria
- Department of Microbiology, Immunology and Genetics, University of Vienna, Max F. Perutz Labs, Vienna, Austria
| | - Torben Falk
- Department of Pharmaceutical Sciences, University of Vienna, Vienna, Austria
- Vienna Doctoral School of Pharmaceutical, Nutritional and Sport, Sciences, University of Vienna, Vienna, Austria
- Department of Microbiology, Immunology and Genetics, University of Vienna, Max F. Perutz Labs, Vienna, Austria
| | - Yunzhan Ning
- Department of Pharmaceutical Sciences, University of Vienna, Vienna, Austria
- Vienna Doctoral School of Pharmaceutical, Nutritional and Sport, Sciences, University of Vienna, Vienna, Austria
- Department of Microbiology, Immunology and Genetics, University of Vienna, Max F. Perutz Labs, Vienna, Austria
| | - Christoph Rademacher
- Department of Pharmaceutical Sciences, University of Vienna, Vienna, Austria
- Department of Microbiology, Immunology and Genetics, University of Vienna, Max F. Perutz Labs, Vienna, Austria
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Pullulan in pharmaceutical and cosmeceutical formulations: A review. Int J Biol Macromol 2023; 231:123353. [PMID: 36681225 DOI: 10.1016/j.ijbiomac.2023.123353] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 01/05/2023] [Accepted: 01/16/2023] [Indexed: 01/19/2023]
Abstract
Pullulan, an α-glucan polysaccharide, is colorless, odorless, non-toxic, non-carcinogenic, highly biocompatible, edible and biodegradable in nature. The long chains of glucopyranose rings in pullulan structure are linked together by α-(1 → 4) and α-(1 → 6) glycosidic linkages. The occurrence of both glycosidic linkages in the pullulan structure contributes to its distinctive properties. The unique structure of pullulan makes it a potent candidate for both pharmaceutical and cosmeceutical applications. In pharmaceuticals, it can be used as a drug carrier and in various dosage formulations. It has been widely used in drug targeting, implants, ocular dosage forms, topical formulations, oral dosage forms, and oral liquid formulations, etc. Pullulan can be used as a potential carrier of active ingredients and their site-specific delivery to skin layers for cosmeceutical applications. It has been extensively used in cosmeceutical formulations like creams, shampoo, lotions, sunscreen, facial packs, etc. The current review highlights applications of pullulan in pharmaceutical and cosmeceutical applications.
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Kumar V, Turnbull WB. Targeted delivery of oligonucleotides using multivalent protein-carbohydrate interactions. Chem Soc Rev 2023; 52:1273-1287. [PMID: 36723021 PMCID: PMC9940626 DOI: 10.1039/d2cs00788f] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Indexed: 02/02/2023]
Abstract
Cell surface protein-carbohydrate interactions are essential for tissue-specific recognition and endocytosis of viruses, some bacteria and their toxins, and many glycoproteins. Often protein-carbohydrate interactions are multivalent - multiple copies of glycans bind simultaneously to multimeric receptors. Multivalency enhances both affinity and binding specificity, and is of interest for targeted delivery of drugs to specific cell types. The first such example of carbohydrate-mediated drug delivery to reach the clinic is Givosiran, a small interfering ribonucleic acid (siRNA) that is conjugated to a trivalent N-acetylgalactosamine (GalNAc) ligand. This ligand enables efficient uptake of the nucleic acid by the asialoglycoprotein receptor (ASGP-R) on hepatocytes. Synthetic multivalent ligands for ASGP-R were among the first 'cluster glycosides' developed at the birth of multivalent glycoscience around 40 years ago. In this review we trace the history of 'GalNAc targeting' from early academic studies to current pharmaceuticals and consider what other opportunities could follow the success of this delivery technology.
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Affiliation(s)
- Vajinder Kumar
- Department of Chemistry, Akal University, Talwandi Sabo, Bathinda, Punjab, India.
- School of Chemistry and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, UK.
| | - W Bruce Turnbull
- School of Chemistry and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, UK.
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Chirayil TJ, Kumar GSV. Sorafenib-Entrapped, Self-Assembled Pullulan–Stearic Acid Biopolymer-Derived Drug Delivery System to PLC/PRF/5 Hepatocellular Carcinoma Model. Int J Nanomedicine 2022; 17:5099-5116. [PMID: 36340185 PMCID: PMC9635392 DOI: 10.2147/ijn.s377354] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2022] [Accepted: 08/21/2022] [Indexed: 11/05/2022] Open
Abstract
Purpose This study aimed to design a prototypic drug delivery system (DDS) made of an amphiphilic, pullulan (Pull)-derived biodegradable polymer for targeting the asialoglycoprotein receptor (ASGPR) overexpressed in HCC. Stearic acid (SA) was conjugated to increase the hydrophobicity of pullulan (Pull-SA). Methods Pullulan (Pull) was linked to stearic acid (SA) after functional group modifications via EDC/NHS chemistry and characterized. Sorafenib tosylate (SRFT) was entrapped in pullulan–stearic acid nanoparticles (Pull-SA-SRFT) and its particle size, zeta potential, entrapment efficiency (EE), loading capacity (LC), and release efficiency was measured. The competence of Pull-SA-SRFT over SRFT in vitro was assessed using the ASGPR over-expressing PLC/PRF/5 hepatocellular carcinoma (HCC) cell line. This was done by studying cytotoxicity by MTT assay and chromosome condensation assay, early apoptosis by annexin-Pi staining, and late apoptosis by live–dead assay. The cellular uptake study was performed by incorporating coumarin-6 (C6) fluorophore in place of SRFT in Pull-SA conjugates. A biodistribution study was conducted in Swiss-albino mice to assess the biocompatibility and targeting properties of SRFT and Pull-SA-SRFT to the liver and other organs at 1, 6, 24, and 48 h. Results The characterization studies of the copolymer confirmed the successful conjugation of Pull-SA. The self-assembled amphiphilic nanocarrier could proficiently entrap the hydrophobic drug SRFT to obtain an entrapment efficiency of 95.6% (Pull-SA-SRFT). Characterization of the synthesized nanoparticles exhibited highly desirable nanoparticle characteristics. In vitro, apoptotic studies urged that Pull-SA-SRFT nanoparticle was delivered more efficiently to HCC than SRFT. The cellular uptake study performed, gave propitious results in 4 hrs. The biodistribution study conducted in immunocompetent mice suggested that Pull-SA-SRFT was delivered more than SRFT to the liver when compared to other organs, and that the system was biocompatible. Conclusion Pull-SA-SRFT is a promisingly safe, biodegradable, cell-specific nanocarrier and a potential candidate to target hydrophobic drugs to HCC.
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Affiliation(s)
- Teena Jacob Chirayil
- Nano Drug Delivery Systems (NDDS), Cancer Biology Division, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala, India
- Research Scholar, Department of Biotechnology, University of Kerala, Thiruvananthapuram, Kerala, India
| | - G S Vinod Kumar
- Nano Drug Delivery Systems (NDDS), Cancer Biology Division, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala, India
- Correspondence: G S Vinod Kumar, Tel +91 471 2781217, Email
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Ye D, Yang X, Ren L, Lu HS, Sun Y, Lin H, Tan L, Wang N, Nguyen G, Bader M, Mullick AE, Danser AHJ, Daugherty A, Jiang Y, Sun Y, Li F, Lu X. (Pro)renin Receptor Inhibition Reduces Plasma Cholesterol and Triglycerides but Does Not Attenuate Atherosclerosis in Atherosclerotic Mice. Front Cardiovasc Med 2022; 8:725203. [PMID: 35004870 PMCID: PMC8739895 DOI: 10.3389/fcvm.2021.725203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 11/11/2021] [Indexed: 11/13/2022] Open
Abstract
Objective: Elevated plasma cholesterol concentrations contributes to ischemic cardiovascular diseases. Recently, we showed that inhibiting hepatic (pro)renin receptor [(P)RR] attenuated diet-induced hypercholesterolemia and hypertriglyceridemia in low-density lipoprotein receptor (LDLR) deficient mice. The purpose of this study was to determine whether inhibiting hepatic (P)RR could attenuate atherosclerosis. Approach and Results: Eight-week-old male LDLR−/− mice were injected with either saline or N-acetylgalactosamine-modified antisense oligonucleotides (G-ASOs) primarily targeting hepatic (P)RR and were fed a western-type diet (WTD) for 16 weeks. (P)RR G-ASOs markedly reduced plasma cholesterol concentrations from 2,211 ± 146 to 1,128 ± 121 mg/dL. Fast protein liquid chromatography (FPLC) analyses revealed that cholesterol in very low-density lipoprotein (VLDL) and intermediate density lipoprotein (IDL)/LDL fraction were potently reduced by (P)RR G-ASOs. Moreover, (P)RR G-ASOs reduced plasma triglyceride concentrations by more than 80%. Strikingly, despite marked reduction in plasma lipid concentrations, atherosclerosis was not reduced but rather increased in these mice. Further testing in ApoE−/− mice confirmed that (P)RR G-ASOs reduced plasma lipid concentrations but not atherosclerosis. Transcriptomic analysis of the aortas revealed that (P)RR G-ASOs induced the expression of the genes involved in immune responses and inflammation. Further investigation revealed that (P)RR G-ASOs also inhibited (P)RR in macrophages and in enhanced inflammatory responses to exogenous stimuli. Moreover, deleting the (P)RR in macrophages resulted in accelerated atherosclerosis in WTD fed ApoE−/− mice. Conclusion: (P)RR G-ASOs reduced the plasma lipids in atherosclerotic mice due to hepatic (P)RR deficiency. However, augmented pro-inflammatory responses in macrophages due to (P)RR downregulation counteracted the beneficial effects of lowered plasma lipid concentrations on atherosclerosis. Our study demonstrated that hepatic (P)RR and macrophage (P)RR played a counteracting role in atherosclerosis.
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Affiliation(s)
- Dien Ye
- Department of Pharmacology, College of Pharmacy, Shenzhen Technology University, Shenzhen, China.,Saha Cardiovascular Research Center and Department of Physiology, University of Kentucky, Lexington, KY, United States.,Division of Pharmacology and Vascular Medicine, Department of Internal Medicine, Erasmus Medical Center, Rotterdam University, Rotterdam, Netherlands
| | - Xiaofei Yang
- Translational Medicine Collaborative Innovation Center, The Second Clinical Medical College (Shenzhen People's Hospital) of Jinan University, Shenzhen, China
| | - Liwei Ren
- Department of Pharmacology, College of Pharmacy, Shenzhen Technology University, Shenzhen, China.,Division of Pharmacology and Vascular Medicine, Department of Internal Medicine, Erasmus Medical Center, Rotterdam University, Rotterdam, Netherlands
| | - Hong S Lu
- Saha Cardiovascular Research Center and Department of Physiology, University of Kentucky, Lexington, KY, United States
| | - Yuan Sun
- Department of Pharmacology, College of Pharmacy, Shenzhen Technology University, Shenzhen, China.,Division of Pharmacology and Vascular Medicine, Department of Internal Medicine, Erasmus Medical Center, Rotterdam University, Rotterdam, Netherlands
| | - Hui Lin
- Department of Pharmacology, College of Pharmacy, Shenzhen Technology University, Shenzhen, China.,Division of Pharmacology and Vascular Medicine, Department of Internal Medicine, Erasmus Medical Center, Rotterdam University, Rotterdam, Netherlands
| | - Lunbo Tan
- Department of Pharmacology, College of Pharmacy, Shenzhen Technology University, Shenzhen, China.,Division of Pharmacology and Vascular Medicine, Department of Internal Medicine, Erasmus Medical Center, Rotterdam University, Rotterdam, Netherlands
| | - Na Wang
- Department of Pharmacology, College of Pharmacy, Shenzhen Technology University, Shenzhen, China.,Division of Pharmacology and Vascular Medicine, Department of Internal Medicine, Erasmus Medical Center, Rotterdam University, Rotterdam, Netherlands
| | - Genevieve Nguyen
- Institut National de la Santé et de la Recherche Médicale (INSERM) and Collège de France Early Development and Pathologies Center for Interdisciplinary Research in Biology and Experimental Medicine Unit, Paris, France
| | - Michael Bader
- Max-Delbrück Center for Molecular Medicine (MDC), Berlin, Germany.,Institute for Biology, University of Lübeck, Lübeck, Germany.,Charité University Medicine, Berlin, Germany.,German Center for Cardiovascular Research (DZHK), Partner Site Berlin, Berlin, Germany
| | | | - A H Jan Danser
- Division of Pharmacology and Vascular Medicine, Department of Internal Medicine, Erasmus Medical Center, Rotterdam University, Rotterdam, Netherlands
| | - Alan Daugherty
- Saha Cardiovascular Research Center and Department of Physiology, University of Kentucky, Lexington, KY, United States
| | - Yizhou Jiang
- Institute for Advanced Study, Shenzhen University, Shenzhen, China
| | - Yidan Sun
- Department of Physiology, Shenzhen University Health Science Center, Shenzhen University, Shenzhen, China
| | - Furong Li
- Translational Medicine Collaborative Innovation Center, The Second Clinical Medical College (Shenzhen People's Hospital) of Jinan University, Shenzhen, China
| | - Xifeng Lu
- Department of Pharmacology, College of Pharmacy, Shenzhen Technology University, Shenzhen, China.,Department of Physiology, Shenzhen University Health Science Center, Shenzhen University, Shenzhen, China
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Ligand conjugate SAR and enhanced delivery in NHP. Mol Ther 2021; 29:2910-2919. [PMID: 34091052 PMCID: PMC8531135 DOI: 10.1016/j.ymthe.2021.06.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 05/04/2021] [Accepted: 06/01/2021] [Indexed: 12/19/2022] Open
Abstract
N-Acetylgalactosamine (GalNAc) conjugated short interfering RNAs (siRNAs) are a leading RNA interference (RNAi) platform allowing targeted inhibition of disease-causing genes in hepatocytes. More than a decade of development has recently resulted in the first approvals for this class of drugs. While substantial effort has been made to improve nucleic acid modification patterns for better payload stability and efficacy, relatively little attention has been given to the GalNAc targeting ligand. In addition, the lack of an intrinsic endosomal release mechanism has limited potency. Here, we report a stepwise analysis of the structure activity relationships (SAR) of the components comprising these targeting ligands. We show that there is relatively little difference in biological performance between bi-, tri-, and tetravalent ligand structures while identifying other features that affect their biological activity more significantly. Further, we demonstrate that subcutaneous co-administration of a GalNAc-functionalized, pH responsive endosomal release agent markedly improved the activity and duration of effect for siRNA conjugates, without compromising tolerability, in non-human primates. These findings could address a significant bottleneck for future siRNA ligand conjugate development.
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ASGR1 and Its Enigmatic Relative, CLEC10A. Int J Mol Sci 2020; 21:ijms21144818. [PMID: 32650396 PMCID: PMC7404283 DOI: 10.3390/ijms21144818] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 07/03/2020] [Accepted: 07/06/2020] [Indexed: 12/19/2022] Open
Abstract
The large family of C-type lectin (CLEC) receptors comprises carbohydrate-binding proteins that require Ca2+ to bind a ligand. The prototypic receptor is the asialoglycoprotein receptor-1 (ASGR1, CLEC4H1) that is expressed primarily by hepatocytes. The early work on ASGR1, which is highly specific for N-acetylgalactosamine (GalNAc), established the foundation for understanding the overall function of CLEC receptors. Cells of the immune system generally express more than one CLEC receptor that serve diverse functions such as pathogen-recognition, initiation of cellular signaling, cellular adhesion, glycoprotein turnover, inflammation and immune responses. The receptor CLEC10A (C-type lectin domain family 10 member A, CD301; also called the macrophage galactose-type lectin, MGL) contains a carbohydrate-recognition domain (CRD) that is homologous to the CRD of ASGR1, and thus, is also specific for GalNAc. CLEC10A is most highly expressed on immature DCs, monocyte-derived DCs, and alternatively activated macrophages (subtype M2a) as well as oocytes and progenitor cells at several stages of embryonic development. This receptor is involved in initiation of TH1, TH2, and TH17 immune responses and induction of tolerance in naïve T cells. Ligand-mediated endocytosis of CLEC receptors initiates a Ca2+ signal that interestingly has different outcomes depending on ligand properties, concentration, and frequency of administration. This review summarizes studies that have been carried out on these receptors.
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Seidi F, Jenjob R, Phakkeeree T, Crespy D. Saccharides, oligosaccharides, and polysaccharides nanoparticles for biomedical applications. J Control Release 2018; 284:188-212. [DOI: 10.1016/j.jconrel.2018.06.026] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 06/18/2018] [Accepted: 06/20/2018] [Indexed: 12/16/2022]
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Sharma VK, Osborn MF, Hassler MR, Echeverria D, Ly S, Ulashchik EA, Martynenko-Makaev YV, Shmanai VV, Zatsepin TS, Khvorova A, Watts JK. Novel Cluster and Monomer-Based GalNAc Structures Induce Effective Uptake of siRNAs in Vitro and in Vivo. Bioconjug Chem 2018; 29:2478-2488. [PMID: 29898368 DOI: 10.1021/acs.bioconjchem.8b00365] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
GalNAc conjugation is emerging as a dominant strategy for delivery of therapeutic oligonucleotides to hepatocytes. The structure and valency of the GalNAc ligand contributes to the potency of the conjugates. Here we present a panel of multivalent GalNAc variants using two different synthetic strategies. Specifically, we present a novel conjugate based on a support-bound trivalent GalNAc cluster, and four others using a GalNAc phosphoramidite monomer that was readily assembled into tri- or tetravalent designs during solid phase oligonucleotide synthesis. We compared these compounds to a clinically used trivalent GalNAc cluster both in vitro and in vivo. In vitro, cluster-based and phosphoramidite-based scaffolds show a similar rate of internalization in primary hepatocytes, with membrane binding observed as early as 5 min. All tested compounds provided potent, dose-dependent silencing, with 2-4% of injected dose recoverable from liver after 1 week. The two preassembled trivalent GalNAc clusters showed higher tissue accumulation and gene silencing relative to di-, tri-, or tetravalent GalNAc conjugates assembled via phosphoramidite chemistry.
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Affiliation(s)
| | | | | | | | | | - Egor A Ulashchik
- Institute of Physical Organic Chemistry , National Academy of Sciences of Belarus , Surganova 13 , 220072 Minsk , Belarus
| | - Yury V Martynenko-Makaev
- Institute of Physical Organic Chemistry , National Academy of Sciences of Belarus , Surganova 13 , 220072 Minsk , Belarus
| | - Vadim V Shmanai
- Institute of Physical Organic Chemistry , National Academy of Sciences of Belarus , Surganova 13 , 220072 Minsk , Belarus
| | - Timofei S Zatsepin
- Center for Translational Biomedicine , Skolkovo Institute of Science and Technology , Skolkovo , 143026 Moscow , Russia.,Department of Chemistry , Lomonosov Moscow State University , Leninskie gory 1-3 , 119992 Moscow , Russia
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Dong H, Wu G, Xu H, Zhang C, Wang J, Gao M, Pang Y, Zhang H, Zhang B, Tian Y, Li Q. N-acetylaminogalactosyl-decorated biodegradable PLGA-TPGS copolymer nanoparticles containing emodin for the active targeting therapy of liver cancer. ARTIFICIAL CELLS NANOMEDICINE AND BIOTECHNOLOGY 2018; 46:260-272. [PMID: 29914275 DOI: 10.1080/21691401.2018.1455055] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Primary liver cancer (PLC) is one of the most common malignant tumours and has the third highest mortality rate worldwide. An active liver-targeting drug delivery system via the asialoglycoprotein receptors expressed in the hepatic parenchyma cells of mammals has become a research focus for the treatment of PLC. N-acetylaminogalactosyl-poly(lactide-co-glycolide)-succinyl-D-α-tocopherol polyethylene glycol 1000 succinate (GalNAc-PLGA-sTPGS) was synthesized to achieve active liver-targeting properties. Emodin (EMO)-loaded GalNAc-PLGA-sTPGS nanoparticles (EGPTN) were prepared with EMO which was selected for its potential antitumour efficacy. The in vitro cellular uptake, mechanism, cytotoxicity, and apoptosis of HepG2 cells were analyzed. The in vivo therapeutic effects of EGPTN were assessed in a PLC mouse model. The results showed that GalNAc-PLGA-sTPGS was successfully synthesized. The cellular uptake assay demonstrated that coumarin 6-loaded GalNAc-PLGA-sTPGS nanoparticles had superior active liver-targeting properties. The results of the cytotoxity and apoptosis studies indicated that EGPTN achieved the highest levels of cytotoxicity and cell apoptotic rate among the nanoparticles examined. Furthermore, EGPTN showed better in vivo therapeutic effects and anticancer efficacy in the PLC mice than did the other groups. Therefore, EGPTN enhanced the anticancer effect of EMO both in vitro and in vivo, making it a potential option for the treatment of PLC.
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Affiliation(s)
- Hao Dong
- a College of Pharmacy , Dalian Medical University , Dalian , China
| | - Guoyu Wu
- b Department of Pharmaceutics , the First Affiliated Hospital of Dalian Medical University , Dalian China
| | - Hong Xu
- c College of Basic Medical Sciences , Dalian Medical University , Dalian , China
| | - Chenghong Zhang
- c College of Basic Medical Sciences , Dalian Medical University , Dalian , China
| | - Jiao Wang
- a College of Pharmacy , Dalian Medical University , Dalian , China
| | - Meng Gao
- a College of Pharmacy , Dalian Medical University , Dalian , China
| | - Yue Pang
- d College of Life Science , Liaoning Normal University , Dalian , China
| | - Houli Zhang
- a College of Pharmacy , Dalian Medical University , Dalian , China
| | - Baojing Zhang
- a College of Pharmacy , Dalian Medical University , Dalian , China
| | - Yan Tian
- a College of Pharmacy , Dalian Medical University , Dalian , China
| | - Qingwei Li
- d College of Life Science , Liaoning Normal University , Dalian , China
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Huang Y. Preclinical and Clinical Advances of GalNAc-Decorated Nucleic Acid Therapeutics. MOLECULAR THERAPY. NUCLEIC ACIDS 2017; 6:116-132. [PMID: 28325278 PMCID: PMC5363494 DOI: 10.1016/j.omtn.2016.12.003] [Citation(s) in RCA: 190] [Impact Index Per Article: 27.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Revised: 12/04/2016] [Accepted: 12/04/2016] [Indexed: 01/03/2023]
Abstract
A main challenge in realizing the full potential of nucleic acid therapeutics is efficient delivery of them into targeted tissues and cells. N-acetylgalactosamine (GalNAc) is a well-defined liver-targeted moiety benefiting from its high affinity with asialoglycoprotein receptor (ASGPR). By conjugating it directly to the oligonucleotides or decorating it to a certain delivery system as a targeting moiety, GalNAc has achieved compelling successes in the development of nucleic acid therapeutics in recent years. Several oligonucleotide modalities are undergoing pivotal clinical studies, followed by a blooming pipeline in the preclinical stage. This review covers the progress of GalNAc-decorated oligonucleotide drugs, including siRNAs, anti-miRs, and ASOs, which provides a panorama for this field.
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Affiliation(s)
- Yuanyu Huang
- Advanced Research Institute for Multidisciplinary Science, Beijing Institute of Technology, Beijing 100081, China; Institute of Molecular Medicine, Peking University, Beijing 100871, China.
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Huang X, Leroux JC, Castagner B. Well-Defined Multivalent Ligands for Hepatocytes Targeting via Asialoglycoprotein Receptor. Bioconjug Chem 2016; 28:283-295. [DOI: 10.1021/acs.bioconjchem.6b00651] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Xiangang Huang
- Institute
of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog-Weg 1-5/10, 8093 Zurich, Switzerland
| | - Jean-Christophe Leroux
- Institute
of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog-Weg 1-5/10, 8093 Zurich, Switzerland
| | - Bastien Castagner
- Department
of Pharmacology and Therapeutics, McGill University, 3655 Prom. Sir-William-Osler, Montréal, Québec H3G 1Y6, Canada
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Kauffman KJ, Webber MJ, Anderson DG. Materials for non-viral intracellular delivery of messenger RNA therapeutics. J Control Release 2015; 240:227-234. [PMID: 26718856 DOI: 10.1016/j.jconrel.2015.12.032] [Citation(s) in RCA: 263] [Impact Index Per Article: 29.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Revised: 12/14/2015] [Accepted: 12/18/2015] [Indexed: 02/06/2023]
Abstract
Though therapeutics based on messenger RNA (mRNA) have broad potential in applications such as protein replacement therapy, cancer immunotherapy, and genomic engineering, their effective intracellular delivery remains a challenge. A chemically diverse suite of delivery materials with origins as materials for cellular transfection of DNA and small interfering RNAs (siRNAs) has recently been reported to have promise as non-viral delivery agents for mRNA. These materials include covalent conjugates, protamine complexes, nanoparticles based on lipids or polymers, and hybrid formulations. This review will highlight the use of delivery materials for mRNA, with a specific focus on their mechanisms of action, routes of administration, and dosages. Additionally, strategies in which these materials can be adapted and optimized to address challenges specific to mRNA delivery are also discussed. The technologies included have shown varying promise for therapeutic use, specifically having been used to deliver mRNA in vivo or exhibiting characteristics that could make in vivo use a possibility. In so doing, it is the intention of this review to provide a comprehensive look at the progress and possibilities in applying nucleic acid delivery technology specifically toward the emerging area of mRNA therapeutics.
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Affiliation(s)
- Kevin J Kauffman
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, 02139, USA; David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, 02139, USA
| | - Matthew J Webber
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, 02139, USA; Department of Anesthesiology, Boston Children's Hospital, Boston, 02122, USA
| | - Daniel G Anderson
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, 02139, USA; David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, 02139, USA; Department of Anesthesiology, Boston Children's Hospital, Boston, 02122, USA; Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, 02139, USA; Harvard-MIT Division of Health Science and Technology, Massachusetts Institute of Technology, Cambridge, 02139, USA.
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Singh RS, Kaur N, Kennedy JF. Pullulan and pullulan derivatives as promising biomolecules for drug and gene targeting. Carbohydr Polym 2015; 123:190-207. [DOI: 10.1016/j.carbpol.2015.01.032] [Citation(s) in RCA: 131] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Revised: 01/03/2015] [Accepted: 01/14/2015] [Indexed: 12/22/2022]
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Dahlman JE, Kauffman KJ, Langer R, Anderson DG. Nanotechnology for in vivo targeted siRNA delivery. ADVANCES IN GENETICS 2014; 88:37-69. [PMID: 25409603 DOI: 10.1016/b978-0-12-800148-6.00003-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Small interfering RNAs (siRNAs) can specifically inhibit gene expression. As a result, they have tremendous scientific and clinical potential. However, the use of these molecules in patients and animal models has been limited by challenges with delivery. Intracellular RNA delivery is difficult; it requires a system that protects the siRNA from degradative nucleases in the bloodstream, minimizes clearance by the reticuloendothelial system, maximizes delivery to the target tissue, and promotes entry into, and out of, an endocytic vesicle. Despite these barriers, recent data suggest that RNA may be targeted to cells of interest in vivo. Herein we outline strategies for targeted siRNA delivery, and describe how these strategies may be improved.
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Affiliation(s)
- James E Dahlman
- The Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA, USA; Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA, USA; David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Kevin J Kauffman
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA; David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Robert Langer
- The Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA, USA; Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA, USA; Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA; David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Daniel G Anderson
- The Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA, USA; Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA, USA; Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA; David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, USA
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16
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Hsu TL, Lin G, Koizumi A, Brehm K, Hada N, Chuang PK, Wong CH, Hsieh SL, Díaz A. The surface carbohydrates of the Echinococcus granulosus larva interact selectively with the rodent Kupffer cell receptor. Mol Biochem Parasitol 2013; 192:55-9. [PMID: 24361107 DOI: 10.1016/j.molbiopara.2013.12.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Revised: 12/06/2013] [Accepted: 12/10/2013] [Indexed: 02/05/2023]
Abstract
The larvae of the cestodes belonging to the genus Echinococcus dwell primarily in mammalian liver. They are protected by the laminated layer (LL), an acellular mucin-based structure. The glycans decorating these mucins constitute the overwhelming majority of molecules exposed by these larvae to their hosts. However, their decoding by host innate immunity has not been studied. Out of 36 mammalian innate receptors with carbohydrate-binding domains, expressed as Fc fusions, only the mouse Kupffer cell receptor (KCR; CLEC4F) bound significantly to the Echinococcus granulosus LL mucins. The receptor also bound the Echinococcus multilocularis LL. Out of several synthetic glycans representing Echinococcus LL structures, the KCR bound strongly in particular to those ending in Galα1-4Galβ1-3 or Galα1-4Galβ1-4GlcNAc, both characteristic LL carbohydrate motifs. LL carbohydrates may be optimized to interact with the KCR, expressed only in liver macrophages, cells known to contribute to the tolerogenic antigen presentation that is characteristic of this organ.
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Affiliation(s)
- Tsui-Ling Hsu
- Genomics Research Center, Academia Sinica, 128 Academia Road, Section 2, Nankang, Taipei 115, Taiwan
| | - Gerardo Lin
- Cátedra de Inmunología, Departamento de Biociencias, Facultad de Química, e Instituto de Química Biológica, Facultad de Ciencias, Universidad de la República, Instituto de Higiene, Av. A. Navarro 3051, Montevideo CP 11600, Uruguay
| | - Akihiko Koizumi
- Faculty of Pharmacy, Keio University, 1-5-30 Shibakoen, Minato-ku, Tokyo 105-8512, Japan
| | - Klaus Brehm
- University of Würzburg, Institute of Hygiene and Microbiology, Josef-Schneider-Straße 2/E1, 97080 Würzburg, Germany
| | - Noriyasu Hada
- Faculty of Pharmacy, Keio University, 1-5-30 Shibakoen, Minato-ku, Tokyo 105-8512, Japan
| | - Po-Kai Chuang
- Genomics Research Center, Academia Sinica, 128 Academia Road, Section 2, Nankang, Taipei 115, Taiwan
| | - Chi-Huey Wong
- Genomics Research Center, Academia Sinica, 128 Academia Road, Section 2, Nankang, Taipei 115, Taiwan
| | - Shie-Liang Hsieh
- Genomics Research Center, Academia Sinica, 128 Academia Road, Section 2, Nankang, Taipei 115, Taiwan; Institute of Microbiology & Immunology, Institute of Clinical Medicine & Infection, and Immunity Center, National Yang-Ming University, No. 155, Sec. 2, Linong Street, Taipei 112, Taiwan
| | - Alvaro Díaz
- Cátedra de Inmunología, Departamento de Biociencias, Facultad de Química, e Instituto de Química Biológica, Facultad de Ciencias, Universidad de la República, Instituto de Higiene, Av. A. Navarro 3051, Montevideo CP 11600, Uruguay.
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17
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Cheng PC, Chiang PF, Lee KM, Yeh CH, Hsu KL, Liu SW, Shen LH, Peng CL, Fan CK, Luo TY. Evaluating the potential of a new isotope-labelled glyco-ligand for estimating the remnant liver function of schistosoma-infected mice. Parasite Immunol 2013; 35:129-139. [PMID: 23216139 DOI: 10.1111/pim.12022] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2012] [Accepted: 11/30/2012] [Indexed: 12/15/2022]
Abstract
A new glyco-derivative compound (OCTAM) was developed and labelled with isotope to form (188) Re-OCTAM as a candidate nuclear medicine imaging agent for testing the liver function. We evaluated the potential of isotope-labelled OCTAM for estimating the remnant liver function in vitro and in vivo schistosoma-infected mice. The affinity of OCTAM to liver asialoglycoprotein receptors (ASGPR) was assessed by competitive inhibition assay in vitro. In vivo assessments were performed to score the remnant liver function in mice at different schistosomal infection stages. OCTAM binds specifically to ASGPR and showed competitive inhibition of anti-ASGPR antibody binding to hepatocytes, and was higher than that of other galactosyl ligands. Micro-SPECT/CT images of uninfected mice revealed strong liver uptake. Quantified serial images of mice infected for 9, 12 and 18 weeks showed delayed liver uptake, and the retention of uptake was inversely correlated with stage and grade of schistosoma infection. Pathological and biochemical analysis demonstrated that gradually accumulating liver injury caused by infection significantly influenced uptake of (188) Re-OCTAM. Hepatic ASGPR expression diminished only in the chronic infection stage. This study demonstrated that the isotope-labelled OCTAM could accumulate in the liver, might have potential as an imaging agent for in vivo hepatic function evaluation of schistosomiasis.
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Affiliation(s)
- P-C Cheng
- Department of Molecular Parasitology and Tropical Diseases, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.,Center for International Tropical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - P-F Chiang
- Isotope Application Division, Institute of Nuclear Energy Research, Taoyuan, Taiwan
| | - K-M Lee
- Institute of Medical Biotechnology, Central Taiwan University of Science and Technology, Taichung, Taiwan
| | - C-H Yeh
- Isotope Application Division, Institute of Nuclear Energy Research, Taoyuan, Taiwan
| | - K-L Hsu
- Isotope Application Division, Institute of Nuclear Energy Research, Taoyuan, Taiwan
| | - S-W Liu
- Chemistry Division, Institute of Nuclear Energy Research, Taoyuan, Taiwan
| | - L-H Shen
- Isotope Application Division, Institute of Nuclear Energy Research, Taoyuan, Taiwan
| | - C-L Peng
- Isotope Application Division, Institute of Nuclear Energy Research, Taoyuan, Taiwan
| | - C-K Fan
- Department of Molecular Parasitology and Tropical Diseases, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.,Center for International Tropical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - T-Y Luo
- Isotope Application Division, Institute of Nuclear Energy Research, Taoyuan, Taiwan
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18
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Jégouzo SAF, Quintero-Martínez A, Ouyang X, dos Santos Á, Taylor ME, Drickamer K. Organization of the extracellular portion of the macrophage galactose receptor: a trimeric cluster of simple binding sites for N-acetylgalactosamine. Glycobiology 2013; 23:853-64. [PMID: 23507965 PMCID: PMC3671775 DOI: 10.1093/glycob/cwt022] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The properties of the human macrophage galactose receptor have been investigated. Specificity for N-acetylgalactosamine (GalNAc) residues with exposed 3- and 4-hydroxyl groups explains virtually all of the results obtained from a recently expanded array of synthetic glycans and is consistent with a model for the structure of the binding site. This simple interaction is sufficient to explain the ability of the receptor to bind to tumor-cell glycans bearing Tn and sialyl-Tn antigens, but not to more elaborate O-linked glycans that predominate on normal cells. This specificity also allows for binding of parasite glycans and screening of an array of bacterial outer membrane oligosaccharides confirms that the receptor binds to a subset of these structures with appropriately exposed GalNAc residues. A key feature of the receptor is the clustering of binding sites in the extracellular portion of the protein, which retains the trimeric structure observed in the cell membrane. Chemical crosslinking, gel filtration, circular dichroism analysis and differential scanning calorimetry demonstrate that this trimeric structure of the receptor is stabilized by an α-helical coiled coil that extends from the surface of the membrane to the globular carbohydrate-recognition domains. The helical neck domains form independent trimerization domains. Taken together, these results indicate that the macrophage galactose receptor shares many of the features of serum mannose-binding protein, in which clusters of monosaccharide-binding sites serve as detectors for a simple epitope that is not common on endogenous cell surface glycans but that is abundant on the surfaces of tumor cells and certain pathogens.
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Affiliation(s)
- Sabine A F Jégouzo
- Department of Life Sciences, Imperial College, Sir Ernst Chain Building, London SW7 2AZ, UK
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19
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Sørensen ALT, Clausen H, Wandall HH. Carbohydrate clearance receptors in transfusion medicine. Biochim Biophys Acta Gen Subj 2012; 1820:1797-808. [PMID: 22846227 DOI: 10.1016/j.bbagen.2012.07.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2012] [Revised: 07/10/2012] [Accepted: 07/20/2012] [Indexed: 10/28/2022]
Abstract
BACKGROUND Complex carbohydrates play important functions for circulation of proteins and cells. They provide protective shields and refraction from non-specific interactions with negative charges from sialic acids to enhance circulatory half-life. For recombinant protein therapeutics carbohydrates are especially important to enhance size and reduce glomerular filtration loss. Carbohydrates are, however, also ligands for a large number of carbohydrate-binding lectins exposed to the circulatory system that serve as scavenger receptors for the innate immune system, or have more specific roles in targeting of glycoproteins and cells. SCOPE OF REVIEW Here we provide an overview of the common lectin receptors that play roles for circulating glycoproteins and cells, and present a discussion of ways to engineer glycosylation of recombinant biologics and cells to improve therapeutic effects. MAJOR CONCLUSIONS While the pharmaceutical industry has learned how to exploit carbohydrates to improve pharmacokinetic properties of recombinant therapeutics, our understanding of how to improve cell-based therapies by manipulation of complex carbohydrates is still at its infancy. Progress with the latter has recently been achieved with cold-stored platelets, where exposure of uncapped glycans lead to rapid clearance from circulation by several lectin-mediated pathways. GENERAL SIGNIFICANCE Understanding lectin-mediated clearance pathways is essential for progress in development of biological pharmaceuticals.
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20
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Mamidyala SK, Dutta S, Chrunyk BA, Préville C, Wang H, Withka JM, McColl A, Subashi TA, Hawrylik SJ, Griffor MC, Kim S, Pfefferkorn JA, Price DA, Menhaji-Klotz E, Mascitti V, Finn M. Glycomimetic Ligands for the Human Asialoglycoprotein Receptor. J Am Chem Soc 2012; 134:1978-81. [DOI: 10.1021/ja2104679] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Sreeman K. Mamidyala
- Department
of Chemistry, The Scripps Research Institute, 10550 North Torrey
Pines Road, La Jolla, California 92037, United States
| | - Sanjay Dutta
- Department
of Chemistry, The Scripps Research Institute, 10550 North Torrey
Pines Road, La Jolla, California 92037, United States
| | - Boris A. Chrunyk
- Pfizer Global Research & Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Cathy Préville
- Pfizer Global Research & Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Hong Wang
- Pfizer Global Research & Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Jane M. Withka
- Pfizer Global Research & Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Alexander McColl
- Pfizer Global Research & Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Timothy A. Subashi
- Pfizer Global Research & Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Steven J. Hawrylik
- Pfizer Global Research & Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Matthew C. Griffor
- Pfizer Global Research & Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Sung Kim
- Pfizer Global Research & Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Jeffrey A. Pfefferkorn
- Pfizer Global Research & Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - David A. Price
- Pfizer Global Research & Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Elnaz Menhaji-Klotz
- Pfizer Global Research & Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Vincent Mascitti
- Pfizer Global Research & Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - M.G. Finn
- Department
of Chemistry, The Scripps Research Institute, 10550 North Torrey
Pines Road, La Jolla, California 92037, United States
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21
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Coombs PJ, Harrison R, Pemberton S, Quintero-Martinez A, Parry S, Haslam SM, Dell A, Taylor ME, Drickamer K. Identification of novel contributions to high-affinity glycoprotein-receptor interactions using engineered ligands. J Mol Biol 2009; 396:685-96. [PMID: 20004209 PMCID: PMC2824085 DOI: 10.1016/j.jmb.2009.11.073] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2009] [Revised: 11/24/2009] [Accepted: 11/25/2009] [Indexed: 01/22/2023]
Abstract
Engineered receptor fragments and glycoprotein ligands employed in different assay formats have been used to dissect the basis for the dramatic enhancement of binding of two model membrane receptors, dendritic cell-specific intercellular adhesion molecule 3-grabbing nonintegrin (DC-SIGN) and the macrophage galactose lectin, to glycoprotein ligands compared to simple sugars. These approaches make it possible to quantify the importance of two major factors that combine to enhance the affinity of single carbohydrate-recognition domains (CRDs) for glycoprotein ligands by 100-to 300-fold. First, the presence of extended binding sites within a single CRD can enhance interaction with branched glycans, resulting in increases of fivefold to 20-fold in affinity. Second, presentation of glycans on a glycoprotein surface increases affinity by 15-to 20-fold, possibly due to low-specificity interactions with the surface of the protein or restriction in the conformation of the glycans. In contrast, when solution-phase networking is avoided, enhancement due to binding of multiple branches of a glycan to multiple CRDs in the oligomeric forms of these receptors is minimal and binding of a receptor oligomer to multiple glycans on a single glycoprotein makes only a twofold contribution to overall affinity. Thus, in these cases, multivalent interactions of individual glycoproteins with individual receptor oligomers have a limited role in achieving high affinity. These findings, combined with considerations of membrane receptor geometry, are consistent with the idea that further enhancement of the binding to multivalent glycoprotein ligands requires interaction of multiple receptor oligomers with the ligands.
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22
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Taylor ME, Drickamer K. Structural insights into what glycan arrays tell us about how glycan-binding proteins interact with their ligands. Glycobiology 2009; 19:1155-62. [PMID: 19528664 PMCID: PMC2757572 DOI: 10.1093/glycob/cwp076] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2009] [Revised: 05/25/2009] [Accepted: 05/25/2009] [Indexed: 01/11/2023] Open
Abstract
Screening of glycan arrays represents a powerful, high-throughput approach to defining oligosaccharide ligands for glycan-binding receptors, commonly referred to as lectins. Correlating results from such arrays with structural analysis of receptor-ligand complexes provide one way to validate the arrays. Using examples drawn from the family of proteins that contain C-type carbohydrate-recognition domains, this review illustrates how information from the arrays reflects the way that selectivity and affinity for glycan ligands is achieved. A range of binding profiles is observed, from very restricted binding to a small set of structurally similar ligands to binding of broad classes of ligands with related terminal sugars and even to failure to bind any of the glycans on an array. These outcomes provide insights into the importance of multiple factors in defining the selectivity of these receptors, including the presence of conformationally defined units in some oligosaccharide ligands, local and extended interactions between glycans and the surfaces of receptors, and steric factors that exclude binding of some ligands.
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Affiliation(s)
| | - Kurt Drickamer
- Division of Molecular Biosciences, Department of Life Sciences, Imperial College, London SW7 2AZ, UK
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23
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Karg SR, Kallio PT. The production of biopharmaceuticals in plant systems. Biotechnol Adv 2009; 27:879-894. [PMID: 19647060 DOI: 10.1016/j.biotechadv.2009.07.002] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2009] [Revised: 07/15/2009] [Accepted: 07/17/2009] [Indexed: 12/20/2022]
Abstract
Biopharmaceuticals present the fastest growing segment in the pharmaceutical industry, with an ever widening scope of applications. Whole plants as well as contained plant cell culture systems are being explored for their potential as cheap, safe, and scalable production hosts. The first plant-derived biopharmaceuticals have now reached the clinic. Many biopharmaceuticals are glycoproteins; as the Golgi N-glycosylation machinery of plants differs from the mammalian machinery, the N-glycoforms introduced on plant-produced proteins need to be taken into consideration. Potent systems have been developed to change the plant N-glycoforms to a desired or even superior form compared to the native mammalian N-glycoforms. This review describes the current status of biopharmaceutical production in plants for industrial applications. The recent advances and tools which have been utilized to generate glycoengineered plants are also summarized and compared with the relevant mammalian systems whenever applicable.
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Affiliation(s)
- Saskia R Karg
- Institute of Microbiology, ETH Zurich, Wolfgang-Pauli Strasse 10, CH-8093 Zürich, Switzerland.
| | - Pauli T Kallio
- Institute of Microbiology, ETH Zurich, Wolfgang-Pauli Strasse 10, CH-8093 Zürich, Switzerland.
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24
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Oo-puthinan S, Maenuma K, Sakakura M, Denda-Nagai K, Tsuiji M, Shimada I, Nakamura-Tsuruta S, Hirabayashi J, Bovin NV, Irimura T. The amino acids involved in the distinct carbohydrate specificities between macrophage galactose-type C-type lectins 1 and 2 (CD301a and b) of mice. Biochim Biophys Acta Gen Subj 2008; 1780:89-100. [DOI: 10.1016/j.bbagen.2007.10.017] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2007] [Revised: 10/16/2007] [Accepted: 10/24/2007] [Indexed: 11/15/2022]
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25
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Balyasnikova IV, Skirgello OE, Binevski PV, Nesterovitch AB, Albrecht RF, Kost OA, Danilov SM. Monoclonal Antibodies 1G12 and 6A12 to the N-domain of human angiotensin-converting enzyme: fine epitope mapping and antibody-based detection of ACE inhibitors in human blood. J Proteome Res 2007; 6:1580-94. [PMID: 17326675 DOI: 10.1021/pr060658x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Angiotensin I-converting enzyme (ACE), a key enzyme in cardiovascular pathophysiology, consists of two homologous domains (N- and C-), each bearing a Zn-dependent active site. ACE inhibitors are among the most prescribed drugs in the treatment of hypertension and cardiac failure. Fine epitope mapping of two monoclonal antibodies (mAb), 1G12 and 6A12, against the N-domain of human ACE, was developed using the N-domain 3D-structure and 21 single and double N-domain mutants. The binding of both mAbs to their epitopes on the N-domain of ACE is significantly diminished by the presence of the C-domain in the two-domain somatic tissue ACE and further diminished by the presence of sialic acid residues on the surface of blood ACE. The binding of these mAbs to blood ACE, however, increased dramatically (5-10-fold) in the presence of ACE inhibitors or EDTA, whereas the effect of these compounds on the binding of the mAbs to somatic tissue ACE was less pronounced and even less for truncated N-domain. This implies that the binding of ACE inhibitors or removal of Zn2+ from ACE active centers causes conformational adjustments in the mutual arrangement of N- and C-domains in the two-domain ACE molecule. As a result, the regions of the epitopes for mAb 1G12 and 6A12 on the N-domain, shielded in somatic ACE by the C-domain globule and additionally shielded in blood ACE by sialic acid residues in the oligosaccharide chains localized on Asn289 and Asn416, become unmasked. Therefore, we demonstrated a possibility to employ these mAbs (1G12 or 6A12) for detection and quantification of the presence of ACE inhibitors in human blood. This method should find wide application in monitoring clinical trials with ACE inhibitors as well as in the development of the approach for personalized medicine by these effective drugs.
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Affiliation(s)
- Irina V Balyasnikova
- Department of Anesthesiology, University of Illinois at Chicago, Illinois 60612, USA
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26
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Understanding the Selectivity Mechanism of the Human Asialoglycoprotein Receptor (ASGP-R) toward Gal- and Man- type Ligands for Predicting Interactions with Exogenous Sugars. Int J Mol Sci 2007. [DOI: 10.3390/i8010013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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27
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Coombs PJ, Taylor ME, Drickamer K. Two categories of mammalian galactose-binding receptors distinguished by glycan array profiling. Glycobiology 2006; 16:1C-7C. [PMID: 16670103 PMCID: PMC1751483 DOI: 10.1093/glycob/cwj126] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Profiling of the four known galactose-binding receptors in the C-type lectin family has been undertaken in parallel on a glycan array. The results are generally consistent with those of previous assays using various different formats, but they provide a direct comparison of the properties of the four receptors, revealing that they fall into two distinct groups. The major subunit of the rat asialoglycoprotein receptor and the rat Kupffer cell receptor show similar broad preferences for GalNAc-terminated glycans, while the rat macrophage galactose lectin and the human scavenger receptor C-type lectin (SRCL) bind more restricted sets of glycans. Both of these receptors bind to Lewis x-type structures, but the macrophage galactose lectin also interacts strongly with biantennary galactose- and GalNAc-terminated glycans. Although the similar glycan-binding profiles for the asialoglycoprotein receptor and the Kupffer cell receptor might suggest that these receptors are functionally redundant, analysis of fibroblasts transfected with full-length Kupffer cell receptor reveals that they fail to endocytose glycosylated ligand.
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Affiliation(s)
- Peter J. Coombs
- Division of Molecular Biosciences, Imperial College, London, SW7 2AZ, UK
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Maureen E. Taylor
- Division of Molecular Biosciences, Imperial College, London, SW7 2AZ, UK
| | - Kurt Drickamer
- Division of Molecular Biosciences, Imperial College, London, SW7 2AZ, UK
- To whom correspondence should be addressed: E-mail: , Telephone: + 44 20 7594 5282, Fax: + 44 20 7594 5207
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28
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Westerlind U, Westman J, Törnquist E, Smith CIE, Oscarson S, Lahmann M, Norberg T. Ligands of the asialoglycoprotein receptor for targeted gene delivery, part 1: Synthesis of and binding studies with biotinylated cluster glycosides containing N-acetylgalactosamine. Glycoconj J 2005; 21:227-41. [PMID: 15486455 DOI: 10.1023/b:glyc.0000045095.86867.c0] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
In order to develop the non-viral Bioplex vector system for targeted delivery of genes to hepatocytes, we have evaluated the structure-function relationship for a number of synthetic ligands designed for specific interaction with the hepatic lectin ASGPr. Biotinylated ligand derivatives containing two, three or six beta-linked N-acetylgalactosamine (GalNAc) residues were synthesized, bound to fluorescent-labeled streptavidin and tested for binding and uptake to HepG2 cells using flow cytometry analysis (FACS). Uptake efficiency increased with number of displayed GalNAc units per ligand, in a receptor dependent manner. Thus, a derivative displaying six GalNAc units showed the highest uptake efficacy both in terms of number of internalizing cells and increased amount of material taken up per each cell. However, this higher efficiency was shown to be due not so much to higher number of sugar units, but to higher accessibility of the sugar units for interaction with the receptor (longer spacer). Improving the flexibility and accessibility of a trimeric GalNAc ligand through use of a longer spacer markedly influenced the uptake efficiency, while increasing the number of GalNAc units per ligand above three only provided a minor contribution to the overall affinity. We hereby report the details of the chemical synthesis of the ligands and the structure-function studies in vitro.
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Affiliation(s)
- Ulrika Westerlind
- Department of Chemistry, Swedish University of Agricultural Sciences, P.O. Box 7015, S-750 07 Uppsala, Sweden
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29
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Bovenschen N, Rijken DC, Havekes LM, van Vlijmen BJM, Mertens K. The B domain of coagulation factor VIII interacts with the asialoglycoprotein receptor. J Thromb Haemost 2005; 3:1257-65. [PMID: 15946216 DOI: 10.1111/j.1538-7836.2005.01389.x] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND Coagulation factor VIII (FVIII) is a heavily glycosylated heterodimeric plasma protein that consists of a heavy (domains A1-A2-B) and light chain (domains A3-C1-C2). It has been well established that the clearance of FVIII from the circulation involves mechanisms that are sensitive to the low-density lipoprotein receptor (LDLR) family antagonist receptor-associated protein (RAP), including LDLR-related protein. Because FVIII clearance in the presence of a bolus injection of RAP still occurs fairly efficient, also RAP-independent mechanisms are likely to be involved. OBJECTIVES In the present study, we investigated the interaction of FVIII with the endocytic lectin asialoglycoprotein receptor (ASGPR) and the physiological relevance thereof. METHODS AND RESULTS Surface plasmon resonance studies demonstrated that FVIII dose-dependently bound to ASGPR with high affinity (Kd approximately 2 nM). FVIII subunits were different in that only the heavy chain displayed high-affinity binding to ASGPR. Studies employing a FVIII variant that lacks the B domain revealed that FVIII-ASGPR complex assembly is driven by structure elements within the B domain of the heavy chain. The FVIII heavy chain-ASGPR interaction required calcium ions and was inhibited by soluble D-galactose. Furthermore, deglycosylation of the FVIII heavy chain by endoglycosidase F completely abrogated the interaction with ASGPR. In clearance experiments in mice, the FVIII mean residence time was prolonged by the ASGPR-antagonist asialo-orosomucoid (ASOR). CONCLUSIONS We conclude that asparagine-linked oligosaccharide structures of the FVIII B domain recognize the carbohydrate recognition domains of ASGPR and that an ASOR-sensitive mechanism, most likely ASGPR, contributes to the catabolism of coagulation FVIII in vivo.
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Affiliation(s)
- N Bovenschen
- Department of Plasma Proteins, Sanquin Research at CLB, Amsterdam, The Netherlands
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Sujatha MS, Sasidhar YU, Balaji PV. Insights into the Role of the Aromatic Residue in Galactose-Binding Sites: MP2/6-311G++** Study on Galactose− and Glucose−Aromatic Residue Analogue Complexes. Biochemistry 2005; 44:8554-62. [PMID: 15938646 DOI: 10.1021/bi050298b] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The presence of an aromatic residue (Trp, Phe, Tyr) facing the nonpolar face of galactose is a common feature of galactose-specific lectins. The interactions such as those between the C-H groups of galactose and the pi-electron cloud of aromatic residues have been characterized as weak hydrogen bonds between soft acids and soft bases, largely governed by dispersive and charge transfer interactions. An analysis of the binding sites of several galactose-specific lectins revealed that the spatial position-orientation of galactose relative to the binding site aromatic residue varies substantially. The effect of variations in position-orientations of galactose on the interaction energies of galactose-aromatic residue complexes has not been determined so far. In view of this, MP2/6-311G++** calculations were performed on galactose- and glucose-aromatic residue analogue complexes in eight position-orientations. The results show that the strength of the C-H...pi interactions in galactose-aromatic residue complexes is comparable to that of a hydrogen bond. Rather than the type of aromatic residue, the position-orientation of the saccharide appears to be more critical in determining the strength of their interactions. Earlier studies have found the binding site aromatic residue to be critical, but its role was not clear. This study shows that the aromatic residue is important for discriminating galactose from glucose, in addition to its contribution to binding energy.
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Affiliation(s)
- Mannargudi S Sujatha
- School of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, India
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31
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Sugawara H, Kusunoki M, Kurisu G, Fujimoto T, Aoyagi H, Hatakeyama T. Characteristic Recognition of N-Acetylgalactosamine by an Invertebrate C-type Lectin, CEL-I, Revealed by X-ray Crystallographic Analysis. J Biol Chem 2004; 279:45219-25. [PMID: 15319425 DOI: 10.1074/jbc.m408840200] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
CEL-I is a C-type lectin, purified from the sea cucumber Cucumaria echinata, that shows a high specificity for N-acetylgalactosamine (GalNAc). We determined the crystal structures of CEL-I and its complex with GalNAc at 2.0 and 1.7 A resolution, respectively. CEL-I forms a disulfide-linked homodimer and contains two intramolecular disulfide bonds, although it lacks one intramolecular disulfide bond that is widely conserved among various C-type carbohydrate recognition domains (CRDs). Although the sequence similarity of CEL-I with other C-type CRDs is low, the overall folding of CEL-I was quite similar to those of other C-type CRDs. The structure of the complex with GalNAc revealed that the basic recognition mode of GalNAc was very similar to that for the GalNAc-binding mutant of the mannose-binding protein. However, the acetamido group of GalNAc appeared to be recognized more strongly by the combination of hydrogen bonds to Arg115 and van der Waals interaction with Gln70. Mutational analyses, in which Gln70 and/or Arg115 were replaced by alanine, confirmed that these residues contributed to GalNAc recognition in a cooperative manner.
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Affiliation(s)
- Hajime Sugawara
- Research Center for Structural and Functional Proteomics, Institute for Protein Research, Osaka University, 3-2 Yamada-oka, Suita, Osaka 565-0871, Japan
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32
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Park EI, Baenziger JU. Closely Related Mammals Have Distinct Asialoglycoprotein Receptor Carbohydrate Specificities. J Biol Chem 2004; 279:40954-9. [PMID: 15262963 DOI: 10.1074/jbc.m406647200] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
We recently reported that the rat asialoglycoprotein receptor binds oligosaccharides terminating with sialic acid (Sia) alpha2,6GalNAc. Despite a high percentage of identical amino acids in their sequences, orthologues of the asialoglycoprotein receptor (ASGP-R) in different mammals differ in their specificity for terminal Siaalpha2,6GalNAc. The recombinant subunit 1 of the ASGP-R from the rat (RHL-1 or rat hepatic lectin) and the mouse (MHL-1 or mouse hepatic lectin), which differ at only 12 positions in the amino acid sequence of their carbohydrate recognition domains, binds Siaalpha2,6GalNAcbeta1,4GlcNAcbeta1,2Man-bovine serum albumin and GalNAcbeta1,4GlcNAcbeta1,2Man-bovine serum albumin in ratios of 16:1.0 and 1.0:1.0, respectively. Mutagenesis was used to show that amino acids both in the immediate vicinity of the proposed binding site for terminal GalNAc and on the alpha2 helix that is distant from the binding site contribute to the specificity for terminal Siaalpha2,6GalNAc. Thus, multiple amino acid sequence alterations in two key locations contribute to the difference in specificity observed for the rat and mouse ASGP-Rs. We hypothesize that the altered specificity of ASPG-R orthologues in such evolutionarily closely related species reflects rapidly changing requirements for recognition of endogenous or exogenous oligosaccharides in vivo.
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Affiliation(s)
- Eric I Park
- Department of Pathology, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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33
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Sujatha MS, Balaji PV. Identification of common structural features of binding sites in galactose-specific proteins. Proteins 2004; 55:44-65. [PMID: 14997539 DOI: 10.1002/prot.10612] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Galactose-binding proteins characterize an important subgroup of sugar-binding proteins that are involved in a variety of biological processes. Structural studies have shown that the Gal-specific proteins encompass a diverse range of primary and tertiary structures. The binding sites for galactose also seem to vary in different protein-galactose complexes. No common binding site features that are shared by the Gal-specific proteins to achieve ligand specificity are so far known. With the assumption that common recognition principles will exist for common substrate recognition, the present study was undertaken to identify and characterize any unique galactose-binding site signature by analyzing the three-dimensional (3D) structures of 18 protein-galactose complexes. These proteins belong to 7 nonhomologous families; thus, there is no sequence or structural similarity across the families. Within each family, the binding site residues and their relative distances were well conserved, but there were no similarities across families. A novel, yet simple, approach was adopted to characterize the binding site residues by representing their relative spatial dispositions in polar coordinates. A combination of the deduced geometrical features with the structural characteristics, such as solvent accessibility and secondary structure type, furnished a potential galactose-binding site signature. The signature was evaluated by incorporation into the program COTRAN to search for potential galactose-binding sites in proteins that share the same fold as the known galactose-binding proteins. COTRAN is able to detect galactose-binding sites with a very high specificity and sensitivity. The deduced galactose-binding site signature is strongly validated and can be used to search for galactose-binding sites in proteins. PROSITE-type signature sequences have also been inferred for galectin and C-type animal lectin-like fold families of Gal-binding proteins.
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Affiliation(s)
- M S Sujatha
- School of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai 400 076, India
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34
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Fadden AJ, Holt OJ, Drickamer K. Molecular characterization of the rat Kupffer cell glycoprotein receptor. Glycobiology 2003; 13:529-37. [PMID: 12672702 DOI: 10.1093/glycob/cwg068] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The Kupffer cell receptor for glycoproteins has been reported to have a role in clearance of galactose- and fucose-terminated glycoproteins from circulation. Although the gene and a cDNA encoding the receptor have been described, there has been little study of the receptor protein. To address some questions about possible ligands and functions for this receptor, fragments representing portions of the extracellular domain have been expressed and characterized. The extracellular domain consists of a trimer stabilized by an extended coiled-coil of alpha-helices. The receptor displays monosaccharide-binding characteristics similar to the hepatic asialoglycoprotein receptor, but with somewhat less selectivity. The two best monosaccharide ligands are GalNAc and galactose. alpha-Methyl fucoside is a particularly poor ligand. Analysis of Kupffer cell receptor binding to glycoproteins and oligosaccharides released from them reveals highest affinity for desialylated, complex N-linked glycans. The best glycoprotein ligands contain multiple highly branched oligosaccharides. A human ortholog of the rat receptor gene does not encode a full-length protein and is not expressed in liver. These characteristics suggest that the receptor may have functions parallel to those of the hepatocyte asialoglycoprotein receptor in some (but not all) mammalian species.
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Affiliation(s)
- Andrew J Fadden
- The Glycobiology Institute, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX21 3QU, United Kingdom
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35
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Sayers EW, Prestegard JH. Conformation of a trimannoside bound to mannose-binding protein by nuclear magnetic resonance and molecular dynamics simulations. Biophys J 2002; 82:2683-99. [PMID: 11964255 PMCID: PMC1302057 DOI: 10.1016/s0006-3495(02)75610-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
A model of the carbohydrate recognition domain of the serum form of mannose-binding protein (MBP) from rat complexed with methyl 3,6-di-O-(alpha-D-mannopyranosyl)-alpha-D-mannopyranoside is presented. Allowed conformations for the bound sugar were derived from simulated annealing protocols incorporating distance restraints computed from transferred NOESY spectra. The resulting sugar conformations were then modeled into the MBP binding site, and these models of the complex were refined using molecular dynamics (MD) simulations in the presence of solvent water. These studies indicate that only one of the two major conformations of the alpha(1-->6) linkage found in solution is significantly populated in the bound state (omega = 60 degrees ), whereas the alpha(1-->3) linkage samples at least two states, similar to its behavior in free solution. The bound conformation allows direct hydrogen bonds to form between the sugar and K182 of MBP, in addition to other water-mediated hydrogen bonds. Estimates of binding constants of candidate complexes based on changes in solvent-accessible surface areas upon binding support the NMR and MD results. These estimates further suggest that the enthalpic gains of the additional sugar-MBP interactions in a trisaccharide as opposed to a monosaccharide are offset by entropic penalties, offering an explanation for previous binding data.
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Affiliation(s)
- Eric W Sayers
- Department of Pharmacology, Yale University, New Haven, Connecticut 06510, USA
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36
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Rensen PC, Sliedregt LA, Ferns M, Kieviet E, van Rossenberg SM, van Leeuwen SH, van Berkel TJ, Biessen EA. Determination of the upper size limit for uptake and processing of ligands by the asialoglycoprotein receptor on hepatocytes in vitro and in vivo. J Biol Chem 2001; 276:37577-84. [PMID: 11479285 DOI: 10.1074/jbc.m101786200] [Citation(s) in RCA: 156] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The asialoglycoprotein receptor (ASGPr) on hepatocytes plays a role in the clearance of desialylated proteins from the serum. Although its sugar preference (N-acetylgalactosamine (GalNAc) >> galactose) and the effects of ligand valency (tetraantennary > triantennary >> diantennary >> monoantennary) and sugar spacing (20 A 10 A 4 A) are well documented, the effect of particle size on recognition and uptake of ligands by the receptor is poorly defined. In the present study, we assessed the maximum ligand size that still allows effective processing by the ASGPr of mouse hepatocytes in vivo and in vitro. Here too, we synthesized a novel glycolipid, which possesses a highly hydrophobic steroid moiety for stable incorporation into liposomes, and a triantennary GalNAc(3)-terminated cluster glycoside with a high nanomolar affinity (2 nm) for the ASGPr. Incorporation of the glycolipid into small (30 nm) [(3)H]cholesteryl oleate-labeled long circulating liposomes (1-50%, w/w) caused a concentration-dependent increase in particle clearance that was liver-specific (reaching 85 +/- 7% of the injected dose at 30 min after injection) and mediated by the ASGPr on hepatocytes, as shown by competition studies with asialoorosomucoid in vivo. By using glycolipid-laden liposomes of various sizes between 30 and 90 nm, it was demonstrated that particles with a diameter of >70 nm could no longer be recognized and processed by the ASGPr in vivo. This threshold size for effective uptake was not related to the physical barrier raised by the fenestrated sinusoidal endothelium, which shields hepatocytes from the circulation, because similar results were obtained by studying the uptake of liposomes on isolated mouse hepatocytes in vitro. From these data we conclude that in addition to the species, valency, and orientation of sugar residues, size is also an important determinant for effective recognition and processing of substrates by the ASGPr. Therefore, these data have important implications for the design of ASGPr-specific carriers that are aimed at hepatocyte-directed delivery of drugs and genes.
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Affiliation(s)
- P C Rensen
- Division of Biopharmaceutics, Leiden/Amsterdam Center for Drug Research, University of Leiden, Sylvius Laboratory, 2300 RA Leiden, The Netherlands.
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37
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Kim SH, Goto M, Akaike T. Specific binding of glucose-derivatized polymers to the asialoglycoprotein receptor of mouse primary hepatocytes. J Biol Chem 2001; 276:35312-9. [PMID: 11390372 DOI: 10.1074/jbc.m009749200] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In this study, we designed a novel amphiphilic poly-(p-N-vinylbenzyl-D-glucuronamide) (PV6Gna) modified at the 6-OH position of glucose for hepatocyte recognition to address the mechanism of the interaction between mouse primary hepatocytes and the PV6Gna. PV6Gna bound to lectins specific for glucose but not galactose as did other glucose-derivatized polymers. However, hepatocyte adhesion onto the PV6Gna surface was inhibited in the presence of galactose and its analogues but not in the presence of glucose and its analogues. We also showed that hepatocyte adhesion to the PV6Gna surface was inhibited dose dependently by asialofetuin (ASF). Interactions between soluble PV6Gna and hepatocytes were inhibited by GalNAc, ASF, and EGTA in flow cytometry analysis using fluorescein isothiocyanate-conjugated PV6Gna. Hepatocyte adhesion to the PV6Gna surface was inhibited more effectively by GalNAc than by methyl beta-D-galactose. In flow cytometry analysis and cell adhesion assay, ASF competed for the inhibition of interaction between PV6Gna and hepatocytes 0.5-4 x 10(5)-fold more effectively than did GalNAc. These results demonstrate involvement of asialoglycoprotein receptors (ASGPRs) in the interaction between PV6Gna and hepatocytes. Furthermore, to clarify the mechanism of the interaction between glycopolymers modified at the 6-OH position of glucose and the hepatocyte, we prepared a gel particle containing 6-O-methacryloyl-d-glucose (PMglc) synthesized by an enzymatic method. ASGPRs could be detected using Western blot analysis following precipitation with PMglc in hepatocyte cell lysate. The precipitation of ASGPRs was inhibited in the presence of galactose, ASF, PV6Gna, and EGTA. The precipitation was inhibited more effectively by GalNAc than by methyl beta-d-galactose. ASGPRs were rarely precipitated by PMglc in the cell lysate that had been treated with ASF-conjugated Sepharose. Taken together, we suggest that mouse primary hepatocytes adhere to the PV6Gna surface mediated by ASGPRs, which specifically interacted with the glycopolymers modified at the C-6 position of glucose.
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Affiliation(s)
- S H Kim
- Department of Biomolecular Engineering, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8501, Japan
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38
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Mitchell DA, Fadden AJ, Drickamer K. A novel mechanism of carbohydrate recognition by the C-type lectins DC-SIGN and DC-SIGNR. Subunit organization and binding to multivalent ligands. J Biol Chem 2001; 276:28939-45. [PMID: 11384997 DOI: 10.1074/jbc.m104565200] [Citation(s) in RCA: 398] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
DC-SIGN and DC-SIGNR are cell-surface receptors that mediate cell-cell interactions within the immune system by binding to intercellular adhesion molecule-3. The receptor polypeptides share 77% amino acid sequence identity and are type II transmembrane proteins. The extracellular domain of each comprises seven 23-residue tandem repeats and a C-terminal C-type carbohydrate-recognition domain (CRD). Cross-linking, equilibrium ultracentrifugation, and circular dichroism studies of soluble recombinant fragments of DC-SIGN and DC-SIGNR have been used to show that the extracellular domain of each receptor is a tetramer stabilized by an alpha-helical stalk. Both DC-SIGN and DC-SIGNR bind ligands bearing mannose and related sugars through the CRDs. The CRDs of DC-SIGN and DC-SIGNR bind Man(9)GlcNAc(2) oligosaccharide 130- and 17-fold more tightly than mannose, and affinity for a glycopeptide bearing two such oligosaccharides is increased by a further factor of 5- to 25-fold. These results indicate that the CRDs contain extended or secondary oligosaccharide binding sites that accommodate mammalian-type glycan structures. When the CRDs are clustered in the tetrameric extracellular domain, their arrangement provides a means of amplifying specificity for multiple glycans on host molecules targeted by DC-SIGN and DC-SIGNR. Binding to clustered oligosaccharides may also explain the interaction of these receptors with the gp120 envelope protein of human immunodeficiency virus-1, which contributes to virus infection.
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Affiliation(s)
- D A Mitchell
- Glycobiology Institute, Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom
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39
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Bianucci AM, Chiellini F. A 3D model for the human hepatic asialoglycoprotein receptor (ASGP-R). J Biomol Struct Dyn 2000; 18:435-51. [PMID: 11149519 DOI: 10.1080/07391102.2000.10506679] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
The human hepatic Asialoglycoprotein Receptor (ASGP-R) consists of two different types of liver specific membrane glycoproteins that bind to terminal galactose and N-acetylgalactosamine residues of serum glycoproteins. The two different polypeptide chains are referred to as two receptor subunits, HH1 and HH2, which are both involved in the activity of the functional receptor. This receptor has served as a model for understanding receptor-mediated endocytosis and carbohydrate mediated recognition phenomena. Here models for the C-terminal extracellular region of both HH1 and HH2 subunit are presented. The standard homology building procedure was modified in order to make it suitable for the modeling problem at hand. The models for the extracellular regions of HH1 and HH2 were initially constructed by exploiting several fragments, belonging to proteins of known 3D structure, and showing high local sequence similarity with respect to the glycoproteins of interest. Putative binding sites were first hypothesized on the basis of the comparison with other complexes of lectins, the crystal structure of which was available in the Protein Data Bank. A model for the complex involving the HH2 subunit and the typical high affinity ligand N-acetylgalactosamine (NacGal) was refined as the first by a suitable combination of MD simulations and Energy Minimization calculations, since it seemed to quickly converge to a plausible structure. An intermediate model for HH1 was then rebuilt on the basis of the refined model for HH2. It was then submitted to a sequence of molecular dynamics simulations with templates which took into account the secondary structure prediction for a final refinement. The structures of small regions of the models, located around the binding sites, were compared with more recent crystallographic data regarding a complex involving the mutant of Mannose Binding Protein QPDWGH (1BCH entry in the Protein Data Bank) and NacGal. This mutant shows high local sequence similarity with HH1 and HH2 at the binding sites. On the basis of the above comparison, different locations of the binding sites were also considered. In addition to other expected interactions, two hydrophobic interactions were observed in the models with Trp residues (positions 243 in HH1 and 181 or 267 in HH2 respectively) and His residues (positions 256 in HHI and 184 in HH2.respectively). The quality of the models was evaluated by the Procheck program and they seemed plausible. This observation together with analogies found between binding sites of the models and IBCH supported the validity of the models. A further validation element arose by comparison between experimental binding data available in the literature about the homologous rat receptor subunits and theoretical interaction energies evaluated, by means of the DOCK 3.5 program, in models for the rat subunits obtained from the corresponding human ones. The new modeling procedure used here appears to be a well-suited method for structural analysis of small regions, located around the ligands, in proteins of unknown 3D structure.
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Affiliation(s)
- A M Bianucci
- Dipartimento di Scienze Farmaceutiche, Universita' di Pisa, Italy.
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Feinberg H, Torgersen D, Drickamer K, Weis WI. Mechanism of pH-dependent N-acetylgalactosamine binding by a functional mimic of the hepatocyte asialoglycoprotein receptor. J Biol Chem 2000; 275:35176-84. [PMID: 10931846 DOI: 10.1074/jbc.m005557200] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Efficient release of ligands from the Ca(2+)-dependent carbohydrate-recognition domain (CRD) of the hepatic asialoglycoprotein receptor at endosomal pH requires a small set of conserved amino acids that includes a critical histidine residue. When these residues are incorporated at corresponding positions in an homologous galactose-binding derivative of serum mannose-binding protein, the pH dependence of ligand binding becomes more like that of the receptor. The modified CRD displays 40-fold preferential binding to N-acetylgalactosamine compared with galactose, making it a good functional mimic of the asialoglycoprotein receptor. In the crystal structure of the modified CRD bound to N-acetylgalactosamine, the histidine (His(202)) contacts the 2-acetamido methyl group and also participates in a network of interactions involving Asp(212), Arg(216), and Tyr(218) that positions a water molecule in a hydrogen bond with the sugar amide group. These interactions appear to produce the preference for N-acetylgalactosamine over galactose and are also likely to influence the pK(a) of His(202). Protonation of His(202) would disrupt its interaction with an asparagine that serves as a ligand for Ca(2+) and sugar. The structure of the modified CRD without sugar displays several different conformations that may represent structures of intermediates in the release of Ca(2+) and sugar ligands caused by protonation of His(202).
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Affiliation(s)
- H Feinberg
- Department of Structural Biology, Stanford University School of Medicine, Stanford, California 94305, USA
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41
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Rivkin E, Tres LL, Kaplan-Kraicer R, Shalgi R, Kierszenbaum AL. Molecular cloning of rat sperm galactosyl receptor, a C-type lectin with in vitro egg binding activity. Mol Reprod Dev 2000; 56:401-11. [PMID: 10862008 DOI: 10.1002/1098-2795(200007)56:3<401::aid-mrd11>3.0.co;2-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Rat sperm galactosyl receptor is a member of the C-type animal lectin family showing preferential binding to N-acetylgalactosamine compared to galactose. Binding is mediated by a Ca(2+)-dependent carbohydrate-recognition domain (CRD) identical to that of the minor variant of rat hepatic lectin receptor 2/3 (RHL-2/3). The molecular organization of the genomic DNA, cDNA, and derived amino acid sequence of rat testis galactosyl receptor have been determined and in vitro fertilization studies were conducted to ascertain its role. We have determined that the rat testis galactosyl receptor gene generates two mRNA species: one species, designated liver-type, is identical to RHL-2/3; the other, designated testis-type, contains one unspliced intron (86 nt) which alters the reading frame and changes the amino acid sequence of the carboxyl terminus. As a result, the CRD (glutamine-proline-aspartic acid/QPD) and flanked Ca(2+)-binding amino acid sequences were not present in the testis-type protein. Northern and Southern blots demonstrated presence of transcripts with unspliced intron in rat sperm but not liver. Similarly, antibody, raised against a synthetic 12-amino acid peptide (p12) encoded by the unspliced intron, recognized in immunoblots a 54 kDa receptor protein in protein extracts from testis but not from liver. Immunofluorescence and immunogold electron microscopy studies demonstrated that both protein species localized on the plasma membrane surface of the head and tail of rat sperm. Furthermore, capacitated rat sperm preincubated with polyclonal antisera to RHL-2/3 or to the CRD of the liver-type galactosyl receptor showed a statistically significant decrease in the in vitro fertilization rate. We conclude that rat sperm galactosyl receptor may play a role in egg binding and that an undetermined molecular mechanism operates to generate two proteins with identical intracellular amino terminal domain but only one of them displays a CRD and associated Ca(2+)-binding sites at the carboxyl terminal extracellular domain.
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Affiliation(s)
- E Rivkin
- Department of Cell Biology and Anatomical Sciences, The City University of New York Medical School, New York, New York
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42
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Kierszenbaum AL, Rivkin E, Chang PL, Tres LL, Olsson CA. Galactosyl receptor, a cell surface C-type lectin of normal and tumoral prostate epithelial cells with binding affinity to endothelial cells. Prostate 2000; 43:175-83. [PMID: 10797492 DOI: 10.1002/(sici)1097-0045(20000515)43:3<175::aid-pros3>3.0.co;2-b] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND The mechanism of bone metastasis of prostate cancer involves the interaction of cell surface receptor(s) on cancer cells with ligand(s) on bone marrow endothelial cell surfaces. The rat galactosyl receptor gene generates two mRNA species by differential splicing: one species encodes a protein identical to the minor form of hepatocyte asialoglycoprotein receptor and displays a galactose/N-acetyl-galactosamine-recognition domain; the other encodes a protein with identical intracellular and transmembrane domains but with a different extracellular domain lacking the carbohydrate-recognition domain (CRD). Both proteins appear to coexist as a heterooligomer on the surface of normal mouse, rat, and human prostate epithelial cells and human prostate cancer cells, including the PC-3 cell line. The CRD of galactosyl receptor mediates adhesion of normal and tumoral prostate cells to the surfaces of a human bone marrow endothelial cell line. The use of inhibitors targeting the CRD would be very valuable in hindering the binding of prostate cancer cells to endothelial cells, thus decreasing the incidence of hematogenous metastasis to bone. METHODS Molecular biology, immunohistochemistry, flow cytometry, and a cell aggregation assay were used to determine the expression and role of the galactosyl receptor in cell adhesion. RESULTS Immunoblotting experiments demonstrated that each component of the heterooligomer has a mass of 54 kDa, ascribed in part to associated carbohydrates. An oligonucleotide probe showed the presence of both galactosyl receptor forms in rat prostate and testis, but not in liver, kidney, and spleen. Antibodies to the CRD and a segment of the nonhomologous extracellular domain of the galactosyl receptor blocked cell adhesion to endothelial cell monolayers. CONCLUSIONS The galactosyl receptor provides a valuable target for the development and use of synthetic ligands capable of disrupting endothelial cell-prostate cancer cell interaction, the first step in prostate cancer bone metastasis.
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Affiliation(s)
- A L Kierszenbaum
- Department of Cell Biology and Anatomical Sciences, City University of New York Medical School, New York, NY 10031, USA.
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Wragg S, Drickamer K. Identification of amino acid residues that determine pH dependence of ligand binding to the asialoglycoprotein receptor during endocytosis. J Biol Chem 1999; 274:35400-6. [PMID: 10585409 DOI: 10.1074/jbc.274.50.35400] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The rat hepatic asialoglycoprotein receptor mediates clearance of galactose- and N-acetylgalactosamine-terminated glycoproteins by endocytosis, binding ligands through a C-type, Ca(2+)-dependent carbohydrate-recognition domain (CRD) at extracellular pH and releasing them at lower pH in endosomes. At physiological Ca(2+) concentrations, the midpoint for ligand release from the CRD of the major subunit of the receptor is pH 7.1. In contrast, the midpoint is pH 5.0 for a galactose-binding derivative of the homologous C-type CRD of serum mannose-binding protein, which would thus not efficiently release ligand at an endosomal pH of 5.4. Site-directed mutagenesis of the CRD from the major subunit of the asialoglycoprotein receptor has been used to identify residues that are essential for efficient release of ligand at endosomal pH. The effects of changes to residues His(256), Asp(266), and Arg(270) singly and in combination indicate that these residues reduce the affinity of the CRD for Ca(2+), so that ligands are released at physiological Ca(2+) concentrations. The proximity of these three residues to the ligand-binding site at Ca(2+) site 2 of the domain suggests that they form a pH-sensitive switch for Ca(2+) and ligand binding. Introduction of histidine and aspartic acid residues into the mannose-binding protein CRD at positions equivalent to His(256) and Asp(266) raises the pH for half-maximal binding of ligand to 6.1. The results, as well as sequence comparisons with other C-type CRDs, confirm the importance of these residues in conferring appropriate pH dependence in this family of domains.
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Affiliation(s)
- S Wragg
- Glycobiology Institute, Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom
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Dalziel M, McFarlane I, Axford JS. Lectin analysis of human immunoglobulin G N-glycan sialylation. Glycoconj J 1999; 16:801-7. [PMID: 11133020 DOI: 10.1023/a:1007183915921] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The lectins Sambucus nigra agglutinin (SNA) and Ricinus communis agglutinin (RCA), specific for alpha2,6 linked sialylation, and terminal galactose respectively were used to study the occurrence, linkage and distribution of human immunoglobulin G (IgG) sialylation. SNA was shown to bind N-glycan alpha2,6-linked sialic acid only. Sialidase analysis confirmed that this is the dominant, if not exclusive linkage. Total IgG sialylation was estimated at 1.0 microg SA/mg IgG (or about 0.5 mole per mole) using a biochemical sialic acid assay. SNA displayed strong binding to the IgG Fab fragment in both its native and denatured state. In contrast, SNA failed to bind the IgG Fc fragment in its native form, but displayed strong binding after the Fc was denatured. This allowed the construction of quantitative assays capable of measuring both IgG Fab and Fc alpha2,6-sialylation without the need for enzymatic peptide digestion.
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Affiliation(s)
- M Dalziel
- ICRF Breast Cancer Biology Group, Thomas Guy House, Guy's Hospital, London, UK.
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45
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Iida S, Yamamoto K, Irimura T. Interaction of human macrophage C-type lectin with O-linked N-acetylgalactosamine residues on mucin glycopeptides. J Biol Chem 1999; 274:10697-705. [PMID: 10196140 DOI: 10.1074/jbc.274.16.10697] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A fluorescein-labeled synthetic peptide, PTTTPITTTTK, was converted into O-glycosylated glycopeptides with various numbers of attached N-acetyl-D-galactosamines (GalNAcs) by in vitro glycosylation with UDP-GalNAc and a microsomal fraction of LS174T human colon carcinoma cells. Glycopeptides with 1, 3, 5, and 6 GalNAc residues (G1, G3, G5, and G6) were obtained, and their sizes were confirmed by matrix-assisted laser desorption ionization time-of-flight mass spectrometry. Their sequences were determined by a peptide sequencer to be PTTTGalNAcPITTTTK for G1, PTGalNAcTTPITGalNAcTGalNAcTTK for G3, PTTGalNAcTGalNAcPITGalNAcTGalNAcTGalNAcTK for G5, and PTGalNAcTGalNAcTGalNAcPITGalNAcTGalNAcTGalNAcTK for G6. A calcium-type human macrophage lectin (HML) was prepared in a recombinant form, and its interaction with these glycopeptides was investigated by surface plasmon resonance (SPR) spectroscopy and fluorescence polarization. The affinity of recombinant HML (rHML) for immobilized glycopeptides increased, as revealed by SPR, in parallel with the number of GalNAc. The highest affinity was obtained when the G6-peptide was immobilized at high density. Fluorescence polarization equilibrium-binding assays also revealed that the affinity of rHML for soluble gly-copeptides increased, depending on the number of attached GalNAcs. Carbohydrate recognition domain (CRD) fragments of HML were prepared, and their affinity for these four glycopeptides was also determined, this affinity was apparently lower than that of rHML. Affinity constants of rHML for the G3- and G5-peptides were 11- and 38-fold higher, respectively, than for the G1-peptide, whereas those of CRD fragments were only 2- and 6-fold higher, respectively. A chemical cross-linking study revealed that rHML but not recombinant CRD forms trimers in an aqueous solution. Thus, preferential binding of densely glycosylated O-linked glycopeptides should be due to the trimer formation of rHML.
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Affiliation(s)
- S Iida
- Laboratory of Cancer Biology and Molecular Immunology, Graduate School of Pharmaceutical Sciences, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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Keir G, Winchester BG, Clayton P. Carbohydrate-deficient glycoprotein syndromes: inborn errors of protein glycosylation. Ann Clin Biochem 1999; 36 ( Pt 1):20-36. [PMID: 10370757 DOI: 10.1177/000456329903600103] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The carbohydrate-deficient glycoprotein (CDG) syndromes (CDGS) are a series of autosomal recessive enzyme deficiencies which result in incomplete glycosylation of plasma proteins. CDGS types Ia and Ib have been related to deficiencies of phosphomannomutase and phosphomannose isomerase, respectively, while CDGS type II results from a deficiency of N-acetylglucosaminyltransferase II. Secondary CDG syndromes are associated with galactosaemia and hereditary fructose intolerance. The diagnosis of CDGS is most easily made by studying the glycoforms of suitable marker proteins using either electrophoresis or isoelectric focusing. This paper reviews the structure of the glycan chains of proteins and structural alterations in CDGS. It also outlines analytical techniques which are useful in the laboratory study of protein glycoforms and the diagnosis of CDGS.
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Affiliation(s)
- G Keir
- Department of Neuroimmunology, National Hospital for Neurology and Neurosurgery, London, UK.
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Ng KK, Park-Snyder S, Weis WI. Ca2+-dependent structural changes in C-type mannose-binding proteins. Biochemistry 1998; 37:17965-76. [PMID: 9922165 DOI: 10.1021/bi981972a] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
C-type animal lectins are a diverse family of proteins which mediate cell-surface carbohydrate-recognition events through a conserved carbohydrate-recognition domain (CRD). Most members of this family possess a carbohydrate-binding activity that depends strictly on the binding of Ca2+ at two sites, designated 1 and 2, in the CRD. The structural transitions associated with Ca2+ binding in C-type lectins have been investigated by determining high-resolution crystal structures of rat serum mannose-binding protein (MBP) bound to one Ho3+ in place of Ca2+, and the apo form of rat liver MBP. The removal of Ca2+ does not affect the core structure of the CRD, but dramatic conformational changes occur in the loops. The most significant structural change in the absence of Ca2+ is the isomerization of a cis-peptide bond preceding a conserved proline residue in Ca2+ site 2. This bond adopts the cis conformation in all Ca2+-bound structures, whereas both cis and trans conformations are observed in the absence of Ca2+. The pattern of structural changes in the three loops that interact with Ca2+ is dictated in large part by the conformation of the prolyl peptide bond. The highly conserved nature of Ca2+ site 2 suggests that the transitions observed in MBPs are general features of Ca2+ binding in C-type lectins.
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Affiliation(s)
- K K Ng
- Department of Structural Biology, Stanford University School of Medicine, California 94305, USA
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Kolatkar AR, Leung AK, Isecke R, Brossmer R, Drickamer K, Weis WI. Mechanism of N-acetylgalactosamine binding to a C-type animal lectin carbohydrate-recognition domain. J Biol Chem 1998; 273:19502-8. [PMID: 9677372 DOI: 10.1074/jbc.273.31.19502] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The mammalian hepatic asialoglycoprotein receptor, a member of the C-type animal lectin family, displays preferential binding to N-acetylgalactosamine compared with galactose. The structural basis for selective binding to N-acetylgalactosamine has been investigated. Regions of the carbohydrate-recognition domain of the receptor believed to be important in preferential binding to N-acetylgalactosamine have been inserted into the homologous carbohydrate-recognition domain of a mannose-binding protein mutant that was previously altered to bind galactose. Introduction of a single histidine residue corresponding to residue 256 of the hepatic asialoglycoprotein receptor was found to cause a 14-fold increase in the relative affinity for N-acetylgalactosamine compared with galactose. The relative ability of various acyl derivatives of galactosamine to compete for binding to this modified carbohydrate-recognition domain suggest that it is a good model for the natural N-acetylgalactosamine binding site of the asialoglycoprotein receptor. Crystallographic analysis of this mutant carbohydrate-recognition domain in complex with N-acetylgalactosamine reveals a direct interaction between the inserted histidine residue and the methyl group of the N-acetyl substituent of the sugar. Evidence for the role of the side chain at position 208 of the receptor in positioning this key histidine residue was obtained from structural analysis and mutagenesis experiments. The corresponding serine residue in the modified carbohydrate-recognition domain of mannose-binding protein forms a hydrogen bond to the imidazole side chain. When this serine residue is changed to valine, loss in selectivity for N-acetylgalactosamine is observed. The structure of this mutant reveals that the beta-branched valine side chain interacts directly with the histidine side chain, resulting in an altered imidazole ring orientation.
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Affiliation(s)
- A R Kolatkar
- Department of Structural Biology, Stanford University School of Medicine, Stanford, California 94305, USA
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Analysis of the site-specific asparagine-linked glycosylation of recombinant human coagulation factor VLLa by glycosidase digestions, liquid chromatography, and mass spectrometry. Mol Biotechnol 1998; 9:195-204. [PMID: 18695951 DOI: 10.1007/bf02915793] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
The two asparagine-linked glycosylation sites of recombinant coagulation factor VIIa have been characterized by glycosidase digestions, size-exclusion chromatography (SEC), and mass spectrometry (MS). Nine structures were characterized as core fucosylated bi- and triantennary structures with 0-3 sialic-acid residues, which were alpha2-3 linked to galactose exclusively. Three of the structures had one or two galactose residues substituted by N-acetylgalactosamine. Significant differences were found between the oligosac-charide profiles for the two glycosylation sites in rFVIIa. At Asn322, the degree of sialylation was lower and higher amounts of structures containing N-acetylgalactosamine were found compared to Asn l45.
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50
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Lis H, Sharon N. Lectins: Carbohydrate-Specific Proteins That Mediate Cellular Recognition. Chem Rev 1998; 98:637-674. [PMID: 11848911 DOI: 10.1021/cr940413g] [Citation(s) in RCA: 1294] [Impact Index Per Article: 49.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Halina Lis
- Department of Membrane Research and Biophysics, The Weizmann Institute of Science, Rehovot 76100, Israel
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