51
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Ahmed A, Peters NR, Fitzgerald MK, Watson JA, Hoffmann FM, Thorson JS. Colchicine glycorandomization influences cytotoxicity and mechanism of action. J Am Chem Soc 2007; 128:14224-5. [PMID: 17076473 DOI: 10.1021/ja064686s] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The reaction of 70 unprotected, diversely functionalized free reducing sugars with methoxyamine-appended colchicine led to the production of a 58-member glycorandomized library. High-throughput cytotoxicity assays revealed glycosylation to modulate specificity and potency. Library members were also identified which, unlike the parent natural product (a destabilizer), stabilized in vitro tubulin polymerization in a manner similar to taxol. This study highlights a simple extension of neoglycorandomization toward amine-bearing scaffolds and the potential benefit of glycosylating nonglycosylated natural products.
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Affiliation(s)
- Aqeel Ahmed
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, USA
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52
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Oppilliart S, Mousseau G, Zhang L, Jia G, Thuéry P, Rousseau B, Cintrat JC. 1-Protected 5-amido 1,2,3-triazoles via ruthenium-catalyzed [3+2] cycloaddition of azides and ynamides. Tetrahedron 2007. [DOI: 10.1016/j.tet.2007.06.008] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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53
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Bode HB, Müller R. Reversible sugar transfer by glycosyltransferases as a tool for natural product (bio)synthesis. Angew Chem Int Ed Engl 2007; 46:2147-50. [PMID: 17300123 DOI: 10.1002/anie.200604671] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Helge B Bode
- Institut für Pharmazeutische, Biotechnologie, Universität des Saarlandes, Gebäude A4.1, 66041 Saarbrücken, Germany.
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54
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Lam KS. New aspects of natural products in drug discovery. Trends Microbiol 2007; 15:279-89. [PMID: 17433686 DOI: 10.1016/j.tim.2007.04.001] [Citation(s) in RCA: 330] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2006] [Revised: 03/26/2007] [Accepted: 04/02/2007] [Indexed: 11/20/2022]
Abstract
During the past 15 years, most large pharmaceutical companies have decreased the screening of natural products for drug discovery in favor of synthetic compound libraries. Main reasons for this include the incompatibility of natural product libraries with high-throughput screening and the marginal improvement in core technologies for natural product screening in the late 1980s and early 1990 s. Recently, the development of new technologies has revolutionized the screening of natural products. Applying these technologies compensates for the inherent limitations of natural products and offers a unique opportunity to re-establish natural products as a major source for drug discovery. Examples of these new advances and technologies are described in this review.
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Affiliation(s)
- Kin S Lam
- Nereus Pharmaceuticals Inc., 10480 Wateridge Circle, San Diego, CA 92121, USA.
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55
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Borisova SA, Zhang C, Takahashi H, Zhang H, Wong AW, Thorson JS, Liu HW. Substrate specificity of the macrolide-glycosylating enzyme pair DesVII/DesVIII: opportunities, limitations, and mechanistic hypotheses. Angew Chem Int Ed Engl 2007; 45:2748-53. [PMID: 16538696 DOI: 10.1002/anie.200503195] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Svetlana A Borisova
- Division of Medicinal Chemistry, College of Pharmacy and Department of Chemistry and Biochemistry, University of Texas, Austin, TX 78712, USA
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56
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Moretti R, Thorson JS. Enhancing the latent nucleotide triphosphate flexibility of the glucose-1-phosphate thymidylyltransferase RmlA. J Biol Chem 2007; 282:16942-7. [PMID: 17434871 DOI: 10.1074/jbc.m701951200] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Nucleotidyltransferases are central to nearly all glycosylation-dependent processes and have been used extensively for the chemoenzymatic synthesis of sugar nucleotides. The determination of the NTP specificity of the model thymidylyltransferase RmlA revealed RmlA to utilize all eight naturally occurring NTPs with varying levels of catalytic efficiency, even in the presence of nonnative sugar-1-phosphates. Guided by structural models, active site engineering of RmlA led to alterations of the inherent pyrimidine/purine bias by up to three orders of magnitude. This study sets the stage for engineering single universal nucleotidyltransferases and also provides new catalysts for the synthesis of novel nucleotide diphosphosugars.
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Affiliation(s)
- Rocco Moretti
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin 53706, USA
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57
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Bode H, Müller R. Reversibler Zuckeraustausch mit Glycosyltransferasen als Methode in der Naturstoff(bio)synthese. Angew Chem Int Ed Engl 2007. [DOI: 10.1002/ange.200604671] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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58
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Timmons SC, Mosher RH, Knowles SA, Jakeman DL. Exploiting nucleotidylyltransferases to prepare sugar nucleotides. Org Lett 2007; 9:857-60. [PMID: 17286408 DOI: 10.1021/ol0630853] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
[reaction: see text] Enzymatic approaches to prepare sugar nucleotides are gaining in importance and offer several advantages over chemical synthesis including high yields and stereospecificity. We report the cloning, expression, and purification of two new wild-type thymidylyltransferases and observed catalysis with a wide variety of substrates. Significant product inhibition was not observed with the enzymes studied over a 24 h period, enabling the efficient preparation of 15 sugar nucleotides, clearly demonstrating the synthetic utility of these biocatalysts.
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Affiliation(s)
- Shannon C Timmons
- Department of Chemistry, Dalhousie University, Halifax, N.S., Canada B3H 4J3
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59
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Doi T, Kinbara A, Inoue H, Takahashi T. Donor-Bound Glycosylation for Various Glycosyl Acceptors: Bidirectional Solid-Phase Semisynthesis of Vancomycin and Its Derivatives. Chem Asian J 2007; 2:188-98. [PMID: 17441153 DOI: 10.1002/asia.200600301] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The glycosidation of a polymer-supported glycosyl donor, N-phenyltrifluoroacetimidate, with various glycosyl acceptors is reported. The application of the polymer-supported N-phenyltrifluoroacetimidate is demonstrated in the synthesis of vancomycin derivatives. 2-O-[2-(azidomethyl)benzoyl]glycosyl imidate was attached to a polymer support at the 6-position by a phenylsulfonate linked with a C13 alkyl spacer. Solid-phase glycosidation with a vancomycin aglycon, selective deprotection of the 2-(azidomethyl)benzoyl group, and glycosylation of the resulting 2-hydroxy group with a vancosamine unit were performed. Nucleophilic cleavage from the polymer support with acetate, chloride, azido, and thioacetate ions provided vancomycin derivatives in pure form after simple purification. The semisynthesis of vancomycin was achieved by deprotection of the acetate derivative.
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Affiliation(s)
- Takayuki Doi
- Department of Applied Chemistry, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro, Tokyo 152-8552, Japan.
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60
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Liu Y, Zhao DM, Lu XH, Wang H, Chen H, Ke Y, Leng L, Cheng MS. Synthesis of bisdesmosidic kryptogenyl saponins using the ‘random glycosylation’ strategy and evaluation of their antitumor activity. Bioorg Med Chem Lett 2007; 17:156-60. [PMID: 17035008 DOI: 10.1016/j.bmcl.2006.09.071] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2006] [Revised: 09/20/2006] [Accepted: 09/22/2006] [Indexed: 11/20/2022]
Abstract
A bisdesmosidic steroidal saponins library, composed of 16 novel kryptogenin glycosides, was set up via six random glycosylation procedures, wherein two compounds showed their antitumor activity against HeLa cell in the preliminary pharmacological research.
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Affiliation(s)
- Yang Liu
- Key Lab of New Drugs Design and Discovery of Liaoning Province, School of Pharmaceutical Engineering, Shenyang Pharmaceutical University, Shenyang 110016, PR China
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61
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Study of high glass transition temperature thermosets made from the copper(I)-catalyzed azide–alkyne cycloaddition reaction. POLYMER 2007. [DOI: 10.1016/j.polymer.2006.10.021] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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62
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Wang ZX, Zhao ZG. Synthesis of 1,4-disubstituted 1,2,3-triazolesviaa three-component reaction in water in the presence of cux (X = Cl, I). J Heterocycl Chem 2007. [DOI: 10.1002/jhet.5570440115] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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63
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Thayer DA, Wong CH. Vancomycin Analogues Containing Monosaccharides Exhibit Improved Antibiotic Activity: A Combined One-Pot Enzymatic Glycosylation and Chemical Diversification Strategy. Chem Asian J 2006; 1:445-52. [PMID: 17441081 DOI: 10.1002/asia.200600084] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Many natural products contain carbohydrate moieties that contribute to their biological activity. Manipulation of the carbohydrate domain of natural products through multiple glycosylations to identify new derivatives with novel biological activities has been a difficult and impractical process. We report a practical one-pot enzymatic approach with regeneration of cosubstrates to synthesize analogues of vancomycin that contain an N-alkyl glucosamine, which exhibited marked improvement in antibiotic activity against a vancomycin-resistant strain of Enterococcus.
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Affiliation(s)
- Desiree A Thayer
- Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA
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64
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Lamb SS, Patel T, Koteva KP, Wright GD. Biosynthesis of sulfated glycopeptide antibiotics by using the sulfotransferase StaL. ACTA ACUST UNITED AC 2006; 13:171-81. [PMID: 16492565 DOI: 10.1016/j.chembiol.2005.12.003] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2005] [Revised: 11/23/2005] [Accepted: 12/06/2005] [Indexed: 11/15/2022]
Abstract
The unique glycopeptide antibiotic A47934, produced by Streptomyces toyocaensis, possesses a nonglycosylated heptapeptide core that is sulfated on the phenolic hydroxyl of the N-terminal 4-hydroxy-L-phenylglycine residue. Genetic and biochemical experiments confirmed that StaL is a sulfotransferase capable of sulfating the predicted crosslinked heptapeptide substrate to produce A47934 both in vivo and in vitro. Incubation of purified His(6)-StaL with various substrates in vitro revealed substrate specificity and yielded two sulfo-glycopeptide antibiotics: sulfo-teicoplanin aglycone and sulfo-teicoplanin. Quantification of the antibacterial activity of desulfo-A47934, A47934, teicoplanin, and sulfo-teicoplanin demonstrated that sulfation slightly increased the minimum inhibitory concentration. This unique modification by sulfation expands glycopeptide diversity with potential application for the development of new antibiotics.
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Affiliation(s)
- Sherry S Lamb
- Antimicrobial Research Centre, Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
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65
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A highly efficient microwave-assisted solvent-free synthesis of α- and β-2′-deoxy-1,2,3-triazolyl-nucleosides. Tetrahedron Lett 2006. [DOI: 10.1016/j.tetlet.2006.05.050] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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66
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Borisova SA, Zhang C, Takahashi H, Zhang H, Wong AW, Thorson JS, Liu HW. Substrate Specificity of the Macrolide-Glycosylating Enzyme Pair DesVII/DesVIII: Opportunities, Limitations, and Mechanistic Hypotheses. Angew Chem Int Ed Engl 2006. [DOI: 10.1002/ange.200503195] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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67
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Ostash B, Walker S. Bacterial transglycosylase inhibitors. Curr Opin Chem Biol 2006; 9:459-66. [PMID: 16118062 DOI: 10.1016/j.cbpa.2005.08.014] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2005] [Accepted: 08/12/2005] [Indexed: 12/01/2022]
Abstract
The spread of bacterial resistance to known antibiotics has inspired interest in previously under-exploited drug targets. The transglycosylation reaction remains a 'black box' in the generally well-studied process of bacterial peptidoglycan biosynthesis, which is a very attractive target for chemotherapeutic intervention. Here, we summarize recent progress in the study of bacterial transglycosylases and the compounds that inhibit them. The transglycosylation reaction is readily targeted by several different classes of natural products, implying that it should be possible to develop drugs that inhibit this process once efficient high-throughput screens and appropriate compound libraries have been developed.
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Affiliation(s)
- Bohdan Ostash
- Department of Microbiology and Molecular Genetics, Harvard Medical School, Boston, MA 02115, USA
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68
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Baltz RH. Marcel Faber Roundtable: is our antibiotic pipeline unproductive because of starvation, constipation or lack of inspiration? J Ind Microbiol Biotechnol 2006; 33:507-13. [PMID: 16418869 DOI: 10.1007/s10295-005-0077-9] [Citation(s) in RCA: 146] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2005] [Accepted: 12/14/2005] [Indexed: 10/25/2022]
Abstract
There are few new antibiotics in the pipeline today. The reasons may include starvation at the front of the pipeline due to inadequate sources of suitable compounds to screen coupled with poorly validated discovery methodologies. A successful antibiotic discovery approach in the past, based upon whole cell antibiotic screening of natural products from actinomycetes and fungi, eventually suffered from constipation in the middle of the pipeline due to rediscovery of known compounds, even though low throughput methodology was employed at the front end. The current lack of productivity may be attributed to the poor choice of strategies to address the discovery of new antibiotics. Recent applications of high throughput in vitro screening of individual antibacterial targets to identify lead compounds from combinatorial chemical libraries, traditional chemical libraries, and partially purified natural product extracts has not produced any significant clinical candidates. The solution to the current dilemma may be to return to natural product whole cell screening. For this approach to work in the current millennium, the process needs to be miniaturized to increase the throughput by orders of magnitude over traditional screening, and the rediscovery of known antibiotics needs to be minimized by methods that can be readily monitored and improved over time.
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Affiliation(s)
- Richard H Baltz
- Cubist Pharmaceuticals, Inc., 65 Hayden Avenue, Lexington, MA 02421, USA.
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69
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Rowan AS, Hamilton CJ. Recent developments in preparative enzymatic syntheses of carbohydrates. Nat Prod Rep 2006; 23:412-43. [PMID: 16741587 DOI: 10.1039/b409898f] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
- Andrew S Rowan
- School of Chemistry and Chemical Engineering, Queen's University Belfast, David Keir Building
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70
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Facile Synthesis of Fréchet Type Dendritic Benzyl Azides and Dendrimer via Cycloaddition Reaction with Tripodal Core. B KOREAN CHEM SOC 2005. [DOI: 10.5012/bkcs.2005.26.11.1790] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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71
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Yang J, Fu X, Liao J, Liu L, Thorson JS. Structure-Based Engineering of E. coli Galactokinase as a First Step toward In Vivo Glycorandomization. ACTA ACUST UNITED AC 2005; 12:657-64. [PMID: 15975511 DOI: 10.1016/j.chembiol.2005.04.009] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2005] [Revised: 03/28/2005] [Accepted: 04/11/2005] [Indexed: 11/17/2022]
Abstract
In vitro glycorandomization is a rapid chemoenzymatic strategy to diversify complex natural product scaffolds. The glycorandomization sugar activation pathway is dependent upon the efficient construction of diverse sugar-1-phosphate libraries. In the context of the previously evolved GalK Y371H "gatekeeper" mutation, the active site M173L mutation described herein presents a kinase with remarkably broadened substrate range to include 28 diverse natural and unnatural sugars. Among these new substrates, 6-azido-6-deoxy-galactose and 6-azido-6-deoxy-glucose present unique chemical probes to assess the utility of an E. coli Y371H/M173L-GalK-overproducing strain to generate unnatural sugar-1-phosphates in vivo. Remarkably, the in vivo conversion of both unnatural sugars rival that demonstrated in vitro. This notable in vivo success stands as the first step toward constructing short sugar-activation pathways in vivo and, ultimately, in vivo natural-product glycorandomization.
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Affiliation(s)
- Jie Yang
- Laboratory for Biosynthetic Chemistry, Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, 777 Highland Avenue, Madison, WI 53705, USA
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