lnu.sePublications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Weak affinity chromatography as a new approach for fragment screening in drug discovery
Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
(Astra & Zeneca AB, SE-431 83 Mölndal, Sweden)
Show others and affiliations
2011 (English)In: Analytical Biochemistry, ISSN 0003-2697, E-ISSN 1096-0309, Vol. 414, no 1, 138-146 p.Article in journal (Refereed) Published
Abstract [en]

Fragment-based drug design (FBDD) is currently being implemented in drug discovery, creating a demand for developing efficient techniques for fragment screening. Due to the intrinsic weak or transient binding of fragments (mM–uM in dissociation constant (KD)) to targets, methods must be sensitive enough to accurately detect and quantify an interaction. This study presents weak affinity chromatography (WAC) as an alternative tool for screening of small fragments. The technology was demonstrated by screening of a selected 23 compound fragment collection of documented binders, mostly amidines, using trypsin and thrombin as model target protease proteins. WAC was proven to be a sensitive, robust, and reproducible technique that also provides information about affinity of a fragment in the range of 1 mM–10uM. Furthermore, it has potential for high throughput as was evidenced by analyzing mixtures in the range of 10 substances by WAC–MS. The accessibility and flexibility of the technology were shown as fragment screening can be performed on standard HPLC equipment. The technology can further be miniaturized and adapted to the requirements of affinity ranges of the fragment library. All these features of WAC make it a potential method in drug discovery for fragment screening.

Place, publisher, year, edition, pages
Elsevier, 2011. Vol. 414, no 1, 138-146 p.
National Category
Medical Biotechnology (with a focus on Cell Biology (including Stem Cell Biology), Molecular Biology, Microbiology, Biochemistry or Biopharmacy) Analytical Chemistry
Research subject
Natural Science, Biochemistry; Natural Science, Biomedical Sciences
Identifiers
URN: urn:nbn:se:lnu:diva-24639DOI: 10.1016/j.ab.2011.02.022Scopus ID: 2-s2.0-79955686355OAI: oai:DiVA.org:lnu-24639DiVA: diva2:608853
Available from: 2013-03-01 Created: 2013-03-01 Last updated: 2017-12-06Bibliographically approved
In thesis
1. Introducing weak affinity chromatography to drug discovery with focus on fragment screening
Open this publication in new window or tab >>Introducing weak affinity chromatography to drug discovery with focus on fragment screening
2013 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Fragment-based drug discovery is an emerging process that has gained popularity in recent years. The process starts from small molecules called fragments. One major step in fragment-based drug discovery is fragment screening, which is a strategy to screen libraries of small molecules to find hits. The strategy in theory is more efficient than traditional high-throughput screening that works with larger molecules. As fragments intrinsically possess weak affinity to a target, detection techniques of high sensitivity to affinity are required for fragment screening. Furthermore, the use of different screening methods is necessary to improve the likelihood of success in finding suitable fragments. Since no single method can work for all types of screening, there is a demand for new techniques. The aim of this thesis is to introduce weak affinity chromatography (WAC) as a novel technique for fragment screening.

WAC is, as the name suggests, an affinity-based liquid chromatographic technique that separates compounds based on their different weak affinities to an immobilized target. The higher affinity a compound has towards the target, the longer it remains in the separation unit, and this will be expressed as a longer retention time. The affinity measure and ranking of affinity can be achieved by processing the obtained retention times of analyzed compounds.

In this thesis, WAC is studied for fragment screening on two platforms. The first system comprised a 24-channel affinity cartridge that works in cooperation with an eight-needle autosampler and 24 parallel UV detector units. The second system was a standard analytical LC-MS platform that is connected to an affinity column, generally called WAC-MS or affinity LC-MS. The evaluation criteria in studying WAC for fragment screening using these platforms were throughput, affinity determination and ranking, specificity, operational platform characteristics and consumption of target protein and sample. The model target proteins were bovine serum albumin for the first platform, thrombin and trypsin for the latter. Screened fragments were either small molecule drugs, a thrombin-directed collection of compounds, or a general-purpose fragment library. To evaluate WAC for early stages of fragment elaboration, diastereomeric mixtures from a thrombin-directed synthesis project were screened.

Although both analytical platforms can be used for fragment screening, WAC-MS shows more useful features due to easy access to the screening platform, higher throughput and ability to analyze mixtures. Affinity data from WAC are in good correlation with IC50 values from enzyme assay experiments. The possibility to distinguish specific from non- specific interactions plays an important role in the interpretation of WAC results. In this thesis, this was achieved by inhibiting the active site of the target protein to measure off-site interactions. WAC proves to be a sensitive, robust, moderate in cost and easy to access technique for fragment screening, and can also be useful in the early stages of fragment evolution.

In conclusion, this thesis has demonstrated the proof of principle of using WAC as a new tool to monitor affinity and to select hits in fragment-based drug discovery. This thesis has indicated the primary possibilities, advantages as well as the limitations of WAC in fragment screening procedures.  In the future, WAC should be evaluated on other targets and fragment libraries in order to realize more fully the potential of the technology.

Place, publisher, year, edition, pages
Växjö: Linnaeus University Press, 2013
Series
Linnaeus University Dissertations, 124/2013
Keyword
affinity LC-MS, fragment-based drug discovery, fragment screening, high throughput, mass spectrometry, stereoisomer, enantiomer, thrombin, weak affinity chromatography, WAC, WAC-MS.
National Category
Medical Biotechnology (with a focus on Cell Biology (including Stem Cell Biology), Molecular Biology, Microbiology, Biochemistry or Biopharmacy)
Research subject
Natural Science, Biomedical Sciences; Natural Science, Biochemistry
Identifiers
urn:nbn:se:lnu:diva-24642 (URN)
Public defence
2013-04-05, N2007, Smålandsgatan 26E, Kalmar, 09:30 (English)
Opponent
Supervisors
Available from: 2013-03-11 Created: 2013-03-01 Last updated: 2013-04-29Bibliographically approved
2. Progress of Weak Affinity Chromatography as a Tool in Drug Development
Open this publication in new window or tab >>Progress of Weak Affinity Chromatography as a Tool in Drug Development
2013 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Weak Affinity Chromatography (WAC) is a technology that was developed to analyse weak (KD > 10-5 M) although selective interactions between biomolecules. The focus of this thesis was to develop this method for various applications in the drug development process.

 

Fragment Based Drug Discovery is a new approach in finding new small molecular drugs. Here, relatively small libraries (a few hundreds to a few thousands of compounds) of fragments (150 – 300 Da) are screened against the target. Fragment hits are then developed into lead molecules by linking, growing or merging fragments binding to different locations of the protein’s active site. However, due to the weakly binding nature of fragments, methods that are able to detect very weak binding events are needed. In this thesis, WAC is presented as a new robust and highly reproducible technology for fragment screening. The technology is demonstrated against a number of different protein targets – proteases, kinases, chaperones and protein-protein interaction (PPI) targets. Comparison of data from fragment screening of 111 fragments by WAC and other more established technologies for fragment screening, such as surface plasmon resonance (SPR) and nuclear magnetic resonance (NMR), validates WAC as a screening technology. It also points at the importance of performing fragment screening by multiple methods as they complement each other.

 

Other applications of WAC in drug development are also presented. The method can be used for chiral separations of racemic mixtures during fragment screening, which enables affinity measurements of individual enantiomers binding to the target of interest. Further, analysis of crude reaction mixtures is shown. By these procedures, the affinity of the product can be assessed directly after synthesis without any time-consuming purification steps. In addition, a high performance liquid chromatography (HPLC) system for highly efficient drug partition studies was developed by stable immobilization of lipid bilayer disks – lipodisks – on a high performance silica support material. These lipodisks are recognized model membranes for drug partition studies. A WAC system with incorporated membrane proteins into immobilized lipodisks has also been produced and evaluated with the ultimate objective to study affinity interactions between ligands and membrane proteins.

Abstract [sv]

Ett läkemedel utövar sin funktion genom att påverka aktiviteten hos ett protein i kroppen då det binder till dess aktiva säte. Förändringen i aktivitet leder till fysiologiska förändringar i kroppen beroende på vilken funktion proteinet har. Med läkemedelsmolekyl avses här en liten organisk molekyl. Fragment-baserad läkemedelsutveckling är en ny metod for att ta fram nya läkemedel. Metoden fungerar genom att man bygger läkemedelsmolekyler utifrån mindre fragment som binder till målproteinet. Fragmenten hittar man genom att screena hela bibliotek av olika fragment mot samma målprotein för att urskilja de som binder till proteinets aktiva säte. Fördelen med den här metoden är bl. a. att med mindre molekyler som utgångspunkt kan en större del av antalet möjliga kombinationer av atomer representeras med ett mindre antal fragment än för större molekyler. Normalt utgörs ett fragmentbibliotek enbart av några hundra till några tusen substanser. Eftersom fragmenten är små har de få interaktionspunker och binder relativt svagt. De svaga bindningarna är svåra att se och mycket känsliga metoder behövs.

 

Svagaffinitetskromatografi är en vätskekromatografisk metod som utvecklades för att studera svaga men mycket selektiva bindningar mellan biomolekyler. Den här avhandlingen syftar till att utveckla metoden för olika användningsområden inom läkemedelsutveckling, främst som en ny metod för fragment-screening. Här mäter man interaktionen mellan ett protein och ett fragment. Proteinet kopplas till ett material som sedan packas i en kolonn i formen av en cylinder. När provet pumpas igenom kolonnen kommer de analyter med affinitet till proteinets aktiva säte att fördröjas på kolonnen i relation till hur starkt de interagerar med målproteinet.

 

I den här avhandlingen presenteras fragment-screening med svagaffinitetskromatografi gentemot ett antal olika typer av målproteiner. Resultatet överensstämmer väl med andra metoder för fragment-screening. Analys av reaktionsblandningar med svagaffinitetskromatografi demonstreras också. Därmed kan bindningen mellan en produkt i en reaktionsblandning och ett målprotein mätas direkt utan föregående uppreningssteg av reaktionsblandningen. Lipodiskar är små diskformade modellmembran som kan användas för att bl. a. mäta hur effektivt läkemedlet tas upp i kroppen vid behandling. Ett system med immobiliserade lipodiskar i en kolonn utvecklades med det framtida målet att kunna arbeta med membranproteiner med svagaffinitetskromatografi.

 

Detta arbete utgör en del i att utveckla svagaffinitetskromatografi som en lättillgänglig och relativt billig metod för användning inom industrin och akademin för läkemedelsutveckling.

Place, publisher, year, edition, pages
Växjö: Linnaeus University Press, 2013
Series
Linnaeus University Dissertations, 138/2013
Keyword
weak affinity chromatography, fragment based drug discovery, fragment screening, thrombin, trypsin, cyclin G-associated kinase, Hsp90, Pin1, cyclooxygenase, lipodisks
National Category
Medical Biotechnology (with a focus on Cell Biology (including Stem Cell Biology), Molecular Biology, Microbiology, Biochemistry or Biopharmacy) Biochemistry and Molecular Biology Analytical Chemistry
Research subject
Chemistry, Biochemistry
Identifiers
urn:nbn:se:lnu:diva-25970 (URN)978-91-87427-33-6 (ISBN)
Public defence
2013-06-14, N2007, Smålandsgatan 26B, Kalmar, 09:30 (English)
Opponent
Supervisors
Available from: 2013-06-18 Created: 2013-05-30 Last updated: 2017-01-27Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full textScopus

Authority records BETA

Duong-Thi, Minh-DaoMeiby, ElinorBergström, MariaIsaksson, RolandOhlson, Sten

Search in DiVA

By author/editor
Duong-Thi, Minh-DaoMeiby, ElinorBergström, MariaIsaksson, RolandOhlson, Sten
By organisation
School of Natural Sciences
In the same journal
Analytical Biochemistry
Medical Biotechnology (with a focus on Cell Biology (including Stem Cell Biology), Molecular Biology, Microbiology, Biochemistry or Biopharmacy)Analytical Chemistry

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 214 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf