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The Journal of Biological Chemistry 2021Controlling unmodified serotonin levels in brain synapses is a primary objective when treating major depressive disorder-a disease that afflicts ∼20% of the world's...
Controlling unmodified serotonin levels in brain synapses is a primary objective when treating major depressive disorder-a disease that afflicts ∼20% of the world's population. Roughly 60% of patients respond poorly to first-line treatments and thus new therapeutic strategies are sought. To this end, we have constructed isoform-specific inhibitors of the human cytosolic sulfotransferase 1A3 (SULT1A3)-the isoform responsible for sulfonating ∼80% of the serotonin in the extracellular brain fluid. The inhibitor design includes a core ring structure, which anchors the inhibitor into a SULT1A3-specific binding pocket located outside the active site, and a side chain crafted to act as a latch to inhibit turnover by fastening down the SULT1A3 active-site cap. The inhibitors are allosteric, they bind with nanomolar affinity and are highly specific for the 1A3 isoform. The cap-stabilizing effects of the latch can be accurately calculated and are predicted to extend throughout the cap and into the surrounding protein. A free-energy correlation demonstrates that the percent inhibition at saturating inhibitor varies linearly with cap stabilization - the correlation is linear because the rate-limiting step of the catalytic cycle, nucleotide release, scales linearly with the fraction of enzyme in the cap-open form. Inhibitor efficacy in cultured cells was studied using a human mammary epithelial cell line that expresses SULT1A3 at levels comparable with those found in neurons. The inhibitors perform similarly in ex vivo and in vitro studies; consequently, SULT1A3 turnover can now be potently suppressed in an isoform-specific manner in human cells.
Topics: Allosteric Site; Arylsulfotransferase; Catecholamines; Depressive Disorder, Major; Epithelial Cells; Humans; Kinetics; Molecular Dynamics Simulation; Molecular Structure; Neurotransmitter Agents; Serotonin; Structure-Activity Relationship; Sulfotransferases
PubMed: 33485192
DOI: 10.1074/jbc.RA120.015177 -
American Journal of Physiology. Cell... Jun 2022Heparan sulfate is a widely expressed polysaccharide in the extracellular matrix and on the cell surface. 3--sulfated heparan sulfate represents only a small percentage... (Review)
Review
Heparan sulfate is a widely expressed polysaccharide in the extracellular matrix and on the cell surface. 3--sulfated heparan sulfate represents only a small percentage of heparan sulfate from biological sources. However, this subpopulation is closely associated with biological functions of heparan sulfate. The 3--sulfated heparan sulfate is biosynthesized by heparan sulfate 3--sulfotransferase, which exists in seven different isoforms. This review article summarizes the recent progress in the substrate specificity studies of different 3--sulfotransferase isoforms involving the use of homogeneous oligosaccharide substrates and crystal structural analysis. The article also reviews a newly developed liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based method to analyze the level of 3--sulfated heparan sulfate with high sensitivity and quantitative capability. This newly emerged technology will provide new tools to study the structure and function relationship of heparan sulfate.
Topics: Chromatography, Liquid; Heparitin Sulfate; Protein Isoforms; Sulfates; Sulfotransferases; Tandem Mass Spectrometry
PubMed: 35417268
DOI: 10.1152/ajpcell.00110.2022 -
Advances in Experimental Medicine and... 2017Sulfonation and desulfation are two opposing processes that represent an important layer of regulation of estrogenic activity via ligand supplies. Enzymatic activities... (Review)
Review
Sulfonation and desulfation are two opposing processes that represent an important layer of regulation of estrogenic activity via ligand supplies. Enzymatic activities of families of enzymes, known as sulfotransferases and sulfatases, lead to structural and functional changes of the steroids, thyroids, xenobiotics, and neurotransmitters. Estrogen sulfotransferase (EST) and steroid sulfatase (STS) represent negative and positive regulation of the estrogen activity, respectively. This is because EST-mediated sulfation deactivates estrogens, whereas STS-mediated desulfation converts the inactive estrogen sulfates to active estrogens. In addition to the known functions of estrogens, EST and STS in reproductive processes, regulation of estrogens and other signal molecules especially at the local tissue levels has gained increased attention in the context of metabolic disease in recent years. EST expression is detectable in the subcutaneous adipose tissue in both obese women and men, and the expression of EST is markedly induced in the livers of rodent models of obesity and type 2 diabetes. STS was found to be upregulated in patients with chronic inflammatory liver diseases. Interestingly, the tissue distribution and the transcriptional regulation of EST and STS exhibit obvious sex and species specificity. EST ablation produces completely opposite metabolic phenotype in female and male obese mice. Adipogenesis is also differentially regulated by EST in murine and human adipocytes. This chapter focuses on the recent progress in our understanding of the expression and regulation EST and STS in the context of metabolic homeostasis.
Topics: Animals; Energy Metabolism; Estrogens; Female; Homeostasis; Humans; Male; Sex Characteristics; Sex Factors; Signal Transduction; Species Specificity; Steryl-Sulfatase; Sulfotransferases
PubMed: 29224107
DOI: 10.1007/978-3-319-70178-3_21 -
PLoS Pathogens Sep 2023Select prion diseases are characterized by widespread cerebral plaque-like deposits of amyloid fibrils enriched in heparan sulfate (HS), a abundant extracellular matrix...
Select prion diseases are characterized by widespread cerebral plaque-like deposits of amyloid fibrils enriched in heparan sulfate (HS), a abundant extracellular matrix component. HS facilitates fibril formation in vitro, yet how HS impacts fibrillar plaque growth within the brain is unclear. Here we found that prion-bound HS chains are highly sulfated, and that the sulfation is essential for accelerating prion conversion in vitro. Using conditional knockout mice to deplete the HS sulfation enzyme, Ndst1 (N-deacetylase / N-sulfotransferase) from neurons or astrocytes, we investigated how reducing HS sulfation impacts survival and prion aggregate distribution during a prion infection. Neuronal Ndst1-depleted mice survived longer and showed fewer and smaller parenchymal plaques, shorter fibrils, and increased vascular amyloid, consistent with enhanced aggregate transit toward perivascular drainage channels. The prolonged survival was strain-dependent, affecting mice infected with extracellular, plaque-forming, but not membrane bound, prions. Live PET imaging revealed rapid clearance of recombinant prion protein monomers into the CSF of neuronal Ndst1- deficient mice, neuronal, further suggesting that HS sulfate groups hinder transit of extracellular prion protein monomers. Our results directly show how a host cofactor slows the spread of prion protein through the extracellular space and identify an enzyme to target to facilitate aggregate clearance.
Topics: Animals; Mice; Heparitin Sulfate; Mice, Knockout; Neurons; Prion Diseases; Prion Proteins; Prions; Sulfotransferases
PubMed: 37747931
DOI: 10.1371/journal.ppat.1011487 -
Expert Opinion on Drug Metabolism &... Jul 2021Cytosolic sulfotransferases (SULTs)-mediated sulfation is critically involved in the metabolism of key endogenous compounds, such as catecholamines and thyroid/steroid... (Review)
Review
INTRODUCTION
Cytosolic sulfotransferases (SULTs)-mediated sulfation is critically involved in the metabolism of key endogenous compounds, such as catecholamines and thyroid/steroid hormones, as well as a variety of drugs and other xenobiotics. Studies performed in the past three decades have yielded a good understanding about the enzymology of the SULTs and their structural biology, phylogenetic relationships, tissue/organ-specific/developmental expression, as well as the regulation of the gene expression. An emerging area is related to the functional impact of the genetic polymorphisms.
AREAS COVERED
The current review aims to summarize our current knowledge about the above-mentioned aspects of the SULT research. An emphasis is on the information concerning the effects of the polymorphisms of the genes on the functional activity of the SULT allozymes and the associated physiological, pharmacological, and clinical implications.
EXPERT OPINION
Elucidation of how SNPs may influence the drug-sulfating activity of SULT allozymes will help understand the differential drug metabolism and eventually aid in formulating personalized drug regimens. Moreover, the information concerning the differential sulfating activities of SULT allozymes toward endogenous compounds may allow for the development of strategies for mitigating anomalies in the metabolism of these endogenous compounds in individuals with certain genotypes.
Topics: Animals; Cytosol; Gene Expression Regulation, Enzymologic; Genotype; Humans; Pharmaceutical Preparations; Polymorphism, Single Nucleotide; Sulfates; Sulfotransferases
PubMed: 34107842
DOI: 10.1080/17425255.2021.1940952 -
The Journal of Steroid Biochemistry and... Jan 2023Xian-Ling-Gu-Bao capsule (XLGB) is a widely prescribed traditional Chinese medicine used for the treatment of osteoporosis. However, it significantly elevates levels of...
Xian-Ling-Gu-Bao capsule (XLGB) is a widely prescribed traditional Chinese medicine used for the treatment of osteoporosis. However, it significantly elevates levels of serum estrogens. Here we aimed to assess the dominant contributors of sulfotransferase (SULT) enzymes to the sulfation of estrogens and identify the effective inhibitors of this pathway in XLGB. First, estrone, 17β-estradiol, and estriol underwent sulfation in human liver S9 extracts. Phenotyping reactions and enzyme kinetics assays revealed that SULT1A1, 1A2, 1A3, 1C4, 1E1, and 2A1 all participated in estrogen sulfation, with SULT1E1 and 1A1 as the most important contributors. The incubation system for these two active enzymes were optimized with Tris-HCl buffer, DL-Dithiothreitol (DTT), MgCl, adenosine 3'-phosphate 5'-phosphosulfate (PAPS), protein concentration, and incubation time. Then, 29 compounds in XLGB were selected to investigate their inhibitory effects and mechanisms against SULT1E1 and 1A1 through kinetic modelling. Moreover, in silico molecular docking was used to validate the obtained results. And finally, the prenylated flavonoids (isobavachin, neobavaisoflavone, etc.) from Psoralea corylifolia L., prenylated flavanols (icariside II) from Epimedium brevicornu Maxim., tanshinones (dihydrotanshinone, tanshinone II-A,) from Salvia miltiorrhiza Bge., and others (corylifol A, corylin) were identified as the most potent inhibitors of estrogen sulfation. Taken together, these findings provide insights into the understanding regioselectivity of estrogen sulfation and identify the effective components of XLGB responsible for the promotion of estrogen levels.
Topics: Humans; Molecular Docking Simulation; Sulfotransferases; Polyphenols; Estrogens
PubMed: 36152789
DOI: 10.1016/j.jsbmb.2022.106182 -
Methods in Molecular Biology (Clifton,... 2022Extracellular sulfatases (SULF1 and SULF2) selectively remove 6-O-sulfate groups (6OS) from heparan sulfate proteoglycans (HSPGs) and by this process control important...
Extracellular sulfatases (SULF1 and SULF2) selectively remove 6-O-sulfate groups (6OS) from heparan sulfate proteoglycans (HSPGs) and by this process control important interactions of HSPGs with extracellular factors including morphogens, growth factors, and extracellular matrix (ECM) components. The expression of SULF1 and SULF2 is dynamically regulated during development and is altered in pathological states such as glioblastoma (GBM), a highly malignant and highly invasive brain cancer. SULF2 protein is increased in an important subset of human GBM and it helps regulate receptor tyrosine kinase (RTK) signaling and tumor growth in a murine model of the disease. By altering ligand binding to HSPGs SULF2 has the potential to modify the extracellular availability of factors important in a number of cell processes including proliferation, chemotaxis, and migration. Diffuse invasion of malignant tumor cells into surrounding healthy brain is a characteristic feature of GBM that makes therapy challenging. Here, we describe methods to assess SULF2 expression in human tumor tissue and cell lines and how to relate this to tumor cell invasion.
Topics: Animals; Brain Neoplasms; Glioblastoma; Humans; Mice; Signal Transduction; Sulfatases; Sulfotransferases
PubMed: 34626397
DOI: 10.1007/978-1-0716-1398-6_33 -
Endocrine Reviews Oct 2015Steroid sulfation and desulfation are fundamental pathways vital for a functional vertebrate endocrine system. After biosynthesis, hydrophobic steroids are sulfated to... (Review)
Review
Steroid sulfation and desulfation are fundamental pathways vital for a functional vertebrate endocrine system. After biosynthesis, hydrophobic steroids are sulfated to expedite circulatory transit. Target cells express transmembrane organic anion-transporting polypeptides that facilitate cellular uptake of sulfated steroids. Once intracellular, sulfatases hydrolyze these steroid sulfate esters to their unconjugated, and usually active, forms. Because most steroids can be sulfated, including cholesterol, pregnenolone, dehydroepiandrosterone, and estrone, understanding the function, tissue distribution, and regulation of sulfation and desulfation processes provides significant insights into normal endocrine function. Not surprisingly, dysregulation of these pathways is associated with numerous pathologies, including steroid-dependent cancers, polycystic ovary syndrome, and X-linked ichthyosis. Here we provide a comprehensive examination of our current knowledge of endocrine-related sulfation and desulfation pathways. We describe the interplay between sulfatases and sulfotransferases, showing how their expression and regulation influences steroid action. Furthermore, we address the role that organic anion-transporting polypeptides play in regulating intracellular steroid concentrations and how their expression patterns influence many pathologies, especially cancer. Finally, the recent advances in pharmacologically targeting steroidogenic pathways will be examined.
Topics: Animals; Biological Transport, Active; Humans; Molecular Targeted Therapy; Multienzyme Complexes; Mutation; Neoplasms; Steroids; Steryl-Sulfatase; Sulfate Adenylyltransferase; Sulfotransferases
PubMed: 26213785
DOI: 10.1210/er.2015-1036 -
The Journal of Biological Chemistry Feb 2019Catecholamine neurotransmitter levels in the synapses of the brain shape human disposition-cognitive flexibility, aggression, depression, and reward seeking-and...
Catecholamine neurotransmitter levels in the synapses of the brain shape human disposition-cognitive flexibility, aggression, depression, and reward seeking-and manipulating these levels is a major objective of the pharmaceutical industry. Certain neurotransmitters are extensively sulfonated and inactivated by human sulfotransferase 1A3 (SULT1A3). To our knowledge, sulfonation as a therapeutic means of regulating transmitter activity has not been explored. Here, we describe the discovery of a SULT1A3 allosteric site that can be used to inhibit the enzyme. The structure of the new site is determined using spin-label-triangulation NMR. The site forms a cleft at the edge of a conserved ∼30-residue active-site cap that must open and close during the catalytic cycle. Allosteres anchor into the site via π-stacking interactions with two residues that sandwich the planar core of the allostere and inhibit the enzyme through cap-stabilizing interactions with substituents attached to the core. Changes in cap free energy were calculated as a function of core substituents and used to design and synthesize a series of inhibitors intended to progressively stabilize the cap and slow turnover. The inhibitors bound tightly (34 nm to 7.4 μm) and exhibited progressive inhibition. The cap-stabilizing effects of the inhibitors were experimentally determined and agreed remarkably well with the theoretical predictions. These studies establish a reliable heuristic for the design of SULT1A3 allosteric inhibitors and demonstrate that the free-energy changes of a small, dynamic loop that is critical for SULT substrate selection and turnover can be calculated accurately.
Topics: Allosteric Regulation; Arylsulfotransferase; Catalytic Domain; Humans; Neurotransmitter Agents; Nuclear Magnetic Resonance, Biomolecular; Protein Structure, Secondary; Spin Labels
PubMed: 30545938
DOI: 10.1074/jbc.RA118.006511 -
Drug Metabolism and Disposition: the... Apr 2016The human sulfotransferases (SULTs) regulate the activities of hundreds, if not thousands, of small molecule metabolites via transfer of the sulfuryl-moiety (-SO3) from... (Review)
Review
The human sulfotransferases (SULTs) regulate the activities of hundreds, if not thousands, of small molecule metabolites via transfer of the sulfuryl-moiety (-SO3) from the nucleotide donor, 3'-phosphoadenosine 5'-phosphosulfate (PAPS) to the hydroxyls and amines of the recipients. Our understanding of the molecular basis of SULT catalysis has expanded considerably in recent years. The basic kinetic mechanism of these enzymes, previously thought to be ordered, has been redefined as random for SULT2A1, a representative member of the superfamily. An active-site cap whose structure and dynamics are highly responsive to nucleotides was discovered and shown to be critical in determining SULT selectivity, a topic of longstanding interest to the field. We now realize that a given SULT can operate in two specificity modes-broad and narrow-depending on the disposition of the cap. More recent work has revealed that the caps of the SULT1A1 are controlled by homotropic allosteric interactions between PAPS molecules bound at the dimer's active sites. These interactions cause the catalytic efficiency of SULT1A1 to vary in a substrate-dependent fashion by as much as two orders of magnitude over a range of PAPS concentrations that spans those found in human tissues. SULT catalysis is further complicated by the fact that these enzymes are frequently inhibited by their substrates. This review provides an overview of the mechanistic features of SULT1A1 that are important for the design and interpretation of SULT1A1 assays.
Topics: Animals; Arylsulfotransferase; Catalytic Domain; Enzyme Assays; Humans; Protein Binding; Protein Structure, Secondary; Substrate Specificity
PubMed: 26658224
DOI: 10.1124/dmd.115.068205