There will first be described prior art describing the chemistry of solid phase synthesis.
A useful review of the preparation of cellulose-bound peptide arrays is Hilpert K et al, Cellulose-bound peptide arrays: Preparation and applications, Biotechnol. Genet. Engineer. Rev. 2007, 24:31-106. Hilpert et al teach that cellulose is a polysaccharide with free hydroxy groups and that, since these hydroxy groups are less reactive than amino groups, the direct attachment of amino acids often leads to low yields. To make the cellulose suitable for the synthesis of peptides, the cellulose surface is modified to change the functionalisation from hydroxy to amino groups. It is further taught that modification of the cellulose often involves insertion of a spacer molecule permitting better access to the amino groups on the cellulose. After functionalisation, the amino acids are taught to be coupled either as an active ester (e.g. pentafluorophenyl ester) solution or as in situ activated mixtures. In situ activation is described as mostly carried out with DIC (N,N′-diisopropyl carbodiimide) and HOBt (N-hydroxybenzotriazole) shortly before coupling. Pages 34-42 of Hilpert et al are referred to here in particular as describing pre-treatment of the cellulose and peptide synthesis. Techniques for screening peptide arrays are described later in the same paper. Hilpert et al mention also non-cellulosic substrates (on page 33) and the synthesis of non-peptidic compounds (on page 43).
Mutulis F et al, J. Comb. Chem. 2003, 5:1-7 describe a method for producing non-random peptide libraries using cotton discs. The discs were activated in (25 v/v % in DCM) TFA (to protonate the hydroxy groups of the cotton). To enable peptide synthesis a handle was attached to the cotton to provide access to reagent molecule and a linker was then attached to the handle to provide a reactive site for Fmoc solid phase synthesis. The handle was 6-aminocaproic acid (H2N—(CH2)5—COOH) and the linker was Fmoc Rink linker 4-[(2,4-dimethoxyphenyl)(Fmoc-amino)methyl]-phenoxyacetic acid. Peptides having different amino acid sequences were then synthesised on different discs.
The synthesis of oligonucleotide arrays on cellulose is described by Frank W et al, Nucl. Acids. Res. 1983, 11:4365-4377. Paper discs were pretreated by coupling protected nucleoside-3′-succinates were coupled to the discs by condensation of their carboxylic functions with the hydroxy groups of the cellulose in the presence of MSNT (1-(mesitylene-sulfonyl)-3-nitro-1,2,4,-triazole). After deprotection, a dimethoxy-tritylated base protected phosphodiester is coupled to the pretreated paper disc and further dimethoxy-tritylated base protected phosphodiester building blocks are linked step by step to form the completed oligonucleotide.
Fromont C et al, Chem. Commun. 2000, 283-284 describes the use of triple branching symmetrical dendrimers to increase the loading of a solid phase in the form of resin beads. The authors describe the synthesis of a tri-branching symmetrical dendrimer on the solid phase with an 18-fold amplification of loading. The tri-functional dendrimer monomers were prepared in bulk by alkylation of tris with acrylonitrile followed by nitrile hydrolysis in a saturated solution of HCl in dry MeOH to give the methyl ester. The hindered amino group of the methyl ester was converted to the corresponding isocyanate by treatment with Boc2O and DMAP as described by Knölker to give a stable symmetrical monomer (Knölker H-J et al, Angew. Chem., Int. Head. Engl. 1995, 34: 2497) an amino methyl polystyrene resin was directly derivatised with the isocyanate. The methyl ester was displaced by propane-1,3-diamine. The process was repeated to give Generation 2.0 dendrimer beads. The use of glass as a substrate for attachment of analytes or biological molecules is well known. For example, Millipore Data Sheet “DNA Nucleoside Controlled Pore Glass (CPG®) media” describes the use of DNA-CPG products for the solid phase synthesis of oligonucleotides using phosphoramidite chemistry. The data sheet is identified as Lit. No. DS0010EN00 Rev. A 03/06.
Shenoy N R et al, Protein Sci. 1992, 1: 58-67 describes the use of carboxylic acid-modified polyethylene as a solid phase support for polypeptides. The peptides are attached by coupling the N-terminal amino group of the peptides to the activated carboxyl groups of the film. The carboxylic acid-modified polyethylene (PE-COOH film) was provided by the Pall Corporation of Long Island, N.Y. The highest yields of covalently attached peptide were obtained when 1,3-dicyclohexylcabrodiimide (DCC) was used as an activating agent.
It is also known to use so-called “CLEAR” resins (Cross-Linked Ethoxylate Acrylic Resin) as supports for solid phase peptide synthesis. Such CLEAR products are described in U.S. Pat. Nos. 5,910,554 and 5,656,707 and are produced by Peptides International, Inc.
Sanghvi Y S et al, Pure and Applied Chemistry, 2001, 73: 175-180 describe reusable solid support chemistries for oligonucleotide synthesis. The reusable solid support technology is based on the use of a hydroquinone diacetic acid spacer arm between the 3′-end of the first nucleoside and the hydroxyl-functionalised support. Details of the chemistry have been published in Pon R T et al, Nucleic Acids Research, 1999, 27: 15-31.
For a review article relating to developments in solid phase synthesis supports see Sucholeiki, Molecular Diversity, 1999, 4: 25-30. The new solid phase synthesis supports described include cross-linked polyoxyethylene-polystyrene and polyoxyethylene-polyoxypropylene and polyamidoamine dendrimers attached to TentaGel support.
The solid phase PEGylation of a protein has been described by Lee B K et al in Bioconjugate Chem., 2007, 18: 1728-1734. Recombinant interferon α-2a was absorbed to a cation exchange resin and PEGylated at the N-terminus by mPEG aldehydes through reductive alkylation using NaBH3CN as reducing agent.
An increasingly important class of polymer is organic semiconductor polymers. Turner D et al, Mat. Res. Soc. Symp. Proc., 2003, 771: L8.8.1-L8.8.5 describes a solid phase synthetic strategy for the production of organic semiconductors. The strategy uses a germanium-based linker and Suzuki-type cross-coupling protocols and has been demonstrated for the iterative synthesis of both a regio-regular oligo-3-alkylthiophene and an oligoarylamine. Turner et al is included herein in its entirety for all purposes, as are references 1, 2, 3 and 4 of Turner et al.
For further information on solid phase synthesis techniques, reagents and substrates see Organic Synthesis on Solid Phase: Supports, Linkers, Reactions, Florencio Zaragoza Dörwald, Wiley-VCH, Second Edition, 2002, ISBN 352730603X.
There will be described next prior art relating to methods performed using a mobile solid phase.
EP 0385433A2 discloses a method and apparatus for continuous synthesis on a solid carrier. The solid carrier, for example in the form of a band or thread, has functional groups and is passed through successive reaction and processing zones in a sequence corresponding to the reaction and processing steps of the synthesis concerned. The reaction and processing zones are in the form of baths of liquid, and the carrier coming from the preceding synthetic step is pressed between a pair of rollers to remove most of the liquid from the preceding step.
EP 1304162A2 discloses a method and apparatus for the preparation of polymer arrays on the surface of a flexible elongate web. The apparatus includes a dispensing head and optionally other treatment stations including reagent baths and water baths, the latter being for rinsing. A detection station may be included for detecting fluorescence. The web is driven through these various stages of the apparatus for successive treatments to be carried out at successive stages.
US 2002/0001544A1 discloses a system and method for high throughput processing of droplets. The droplets are dispensed onto a moving surface from one or more reagent addition stations through which the moving surface moves. A combinatorial synthesis may be accomplished and assays can be performed directly on the chemical reaction products on the moving surface.
All the above prior art documents are included herein by reference in their entirety for all purposes.
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