Solid supports cotton

Camarero, J.A., Cotton, G.J., Adeva, A., and Muir, T.W. (1998) Chemical ligation of unprotected peptides directly from a solid support./. Pept. Res. 51(4), 303-316. 

Immobilization. The fixing property of PEIs has previously been discussed. Another application of this property is enzyme immobilization (419). Enzymes can be bound by reactive compounds, eg, isothiocyanate (420) to the PEI skeleton, or immobilized on solid supports, eg, cotton by adhesion with the aid of PEIs. In every case, fixing considerably simplifies the performance of enzyme-catalyzed reactions, thus facilitating preparative work. This technique has been applied to glutaraldehyde-sensitive enzymes (421), a-glucose transferase (422), and pectin lyase, pectin esterase, and endopolygalacturonase (423). 

Gates, B. C., Metal cluster catalysts dispersed on solid supports, in Catalysis by Di- and Polynuclear Metal Cluster Complexes (R. D. Adams and F. A. Cotton, Eds.), p. 509. Wiley-VCH, New York, 1998. 

Centrifugation is a powerful technique allowing the parallel processing of an unlimited number of reaction compartments (101). The first centrifugal multiple peptide synthesizer, Compas 242 (76,102), utilized centrifugation for liquid removal from the functionalized cotton used as the solid support or from resin contained in polypropylene mesh bags (703). This system enabled the automation of tea-bag synthetic methodology. In principle, however, separation of solid and liquid phases was still accomplished by filtration. 

A peptide library can be synthesized using the SPOT synthesis technique to form a low-density peptide spot array (e.g., 25 spots/cm ). In this method, different peptides are synthesized in situ as low-density arrays on cellulose membrane or paper (8). The volume of Fmoc-amino acids and coupling reagents dispensed creates a specific SPOT size that determines both the scale of reaction and the absolute number of peptides that can be arranged on an area of a membrane. Cotton (another form of cellulose) and polystyrene-grafted polyethylene film segments also have been used as solid supports. Recently, polymeric membranes that are chemically, mechanically, and thermally more stable have been developed, which include hydroxy-functionalized PEG acrylate polypropylene membranes and an amino-functionalized ester-free PEG... 

The above list of solid supports is by no means exhaustive. Many others have been proposed and evaluated for use in peptide synthesis, including polypropylene membranes, cotton, controlled-pore glass beads, polyethylene sheets, and others. 

Peptides synthesised and assayed as individuals or mixtures on solid supports such as pins, resin beads, cotton, the silicon surface of microchips or cellulose membranes. ... 

Results and Discussion The solid support Glycyl-cotton... 

The choice of the filter medium is often the most important consideration to ensure efficient operation of a filter. Its function is generally to act as a support for the filter cake, while the initial layers of cake provide the actual filter. The filter medium should be selected primarily on the basis of its ability to retain solids without binding. It should be mechanically strong and corrosion resistant, and should offer as little resistance as possible to the flow of the filtrate. The media are made from widely different materials such as cotton, wool, linen, nylon, jute, silk, glass fiber, porous carbon, metals, rayon and other synthetics, and miscellaneous materials like porous rubber. Cotton fabrics are most commonly used because they are available in a wide variety of weaves, and are cheap. 

Tape and film are the most common forms of solid epoxy adhesives. Tape and film are terms that are used rather loosely for adhesives in a thin sheet form. The term tape generally refers to an adhesive that is supported on a web of paper or nonwoven fabric, or on an open-weave scrim of glass, cotton, or nylon. Films, on the other hand, are free of supporting material and consist only of the adhesive. Both tape and film products may be accompanied with a release liner depending on the tack or blocking characteristics of the adhesive. 

While gellike and macroporous resins cover the vast majority of SPS, the use of other supports has also been explored. Cellulose (33, 34) in the form of paper sheets has been employed for multiple simultaneous SPS of peptides with a relatively low loading of 0.5-0.6 j,mol/cm. Cotton (35) has been used for the same application with a loading of around 0.1 mmol/g. Glass (36) was among the first supports used for the synthesis of large numbers of peptides, due to its chemical inertness and solidity. Various polymeric membranes (37, 38) were also used to prepare peptides on SP. Several of these supports will be mentioned also as related to combinatorial hbrary synthesis (see Section 6.4.1 and 6.4.2). 

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