Shape solid support

The field of synthetic enzyme models encompasses attempts to prepare enzymelike functional macromolecules by chemical synthesis [30]. One particularly relevant approach to such enzyme mimics concerns dendrimers, which are treelike synthetic macromolecules with a globular shape similar to a folded protein, and useful in a range of applications including catalysis [31]. Peptide dendrimers, which, like proteins, are composed of amino acids, are particularly well suited as mimics for proteins and enzymes [32]. These dendrimers can be prepared using combinatorial chemistry methods on solid support [33], similar to those used in the context of catalyst and ligand discovery programs in chemistry [34]. Peptide dendrimers used multivalency effects at the dendrimer surface to trigger cooperativity between amino acids, as has been observed in various esterase enzyme models [35]. 

Our library synthesis was carried out with a set of 27 tube-shaped solid phase synthesis support, called MicroTubes. These supports are prepared by radiation grafting of polystyrene ( — 350 pmol) onto polypropylene tubes, chemically functionalizing the polystyrene with aminomethyl groups to afford about 55 imol of amine per tube, inserting a reusable Rf ID tag into each tube, and heat-sealing the tube ends to prevent loss of the tag. The chemical conversion of all 36 aminomethyl tubes was carried out simultaneously using standard procedures with rink amide linker, each with —46 pmol of available amine per tube.1 2... 

Solid supports for RP-HPLC are, in most cases, silica gel derivatized with cyano, C4, C8, Q8, or diphenyl groups and, therefore, have limited stability at pH values <2.0 or >8.0. Less commonly used supports are polymer based that will withstand high pH. Besides their carbon load, silica gel particles can be of different sizes, shapes, and with pore sizes ranging from 80 to 500 A. Literally hundreds of different columns are available.147 48 A commonly used particle is spherical, 5 pm in diameter, and with 300-A pore size. Whereas C4 and C8 columns are preferred for proteins or very hydrophobic peptides, C18 is most commonly used for a wide variety of peptides. 

This typically consists of a 2-10 mm OD stainless steel tube of 1-2 m length wound into a single or double helix or shaped into a U-tube. Many different packings solid supports) are available (e.g. glass beads, activated charcoal, activated alumina, etc.) which are coated with a selected solvent stationary phase). There are many of the... 

The mode of deposition of a Langmuir film from the air/water interface to a solid- support is determined by the shape of the water miniscus during transfer at the interface. This shape is... 

Many of the catalysts for the hydrodesulfurization process are produced by combining (Table 5-5) a transition metal (or its salt) with a solid support. The metal constituent is the active catalyst. The most commonly used materials for supports are alumina, silica, silica-alumina, kieselguhr, magnesia (and other metal oxides), as well as the zeolites. The support can be manufactured in a variety of shapes or may even be crushed to particles of the desired size. The metal constituent can then be added by contact of the support with an aqueous solution of the metal salt. The whole is then subjected to further treatment that will dictate the final form of the metal on the support (i.e., the metal oxide, the metal sulfide, or even the metal itself). 

Insolubility is, of course, the most fundamental property of a polymer support for it to be useful in peptide synthesis, but it is not the only relevant one. Particle size and shape as well as mechanical stability are important in order to permit easy manipulation and rapid filtration from liquids. Mechanical stability is especially critical when the solid support is to be used in a continuous-flow peptide synthesizer. 

The stationary phase in HPLC is the solid support contained in within a specified column over which the mobile phase flows effecting the separation of the individual components. The HPLC column is normally fabricated using 100- to 300-mm long stainless steel tubes with an internal diameter of 2-5 mm. They are packed with porous, microporous, spherical, or irregularly shaped particles, or particles with specific coatings with the following characteristics. 

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