PEGA resin

H-Cys(Trt)-Tyr(tBu)-Ile-Gln(Trt)-Asn(Trt)-Cys(Trt)-Pro-Leu-Gly-Rink-Linker-PEGA-resin (60mg, 0.09 mmol g 1,5.4 pmol) was suspended in 95% aq TFA (10 mL) for 1 h at rt, followed by the addition of DMSO (2mL) at 0°C. After 30 min at 0°C and 1 h at rt, the resin was rinsed with 95% aq AcOH. The solvent was removed under reduced pressure and the product precipitated with cold Et20 and purified by HPLC yield 3.0 mg (56%). The product was characterized by MALDI-MS, amino acid analysis, and HPLC. 

The Sharpless asymmetric dehydroxylation of resin-bound olefins was monitored using 3H, 13C and HMQC HRMAS NMR.63 The authors found 13C HRMAS NMR to be particularly suited to evaluating the progress of this reaction and permitted the enantiomeric excesses of the products to be determined before they were cleaved from the support. Most importantly, they were able to evaluate the types of substrates amenable to this reaction on solid supports, showing the ability of HRMAS NMR to contribute to synthetic questions. Transformation of the unnatural amino acid Lys(NH2) on a poly (ethylene glycol)-dimethylacrylamide (PEGA) resin to 6-hydroxynorleucine was confirmed by application of TOCSY HRMAS experiments.64... 

Meldal M, Auzanneau FI, Hindsgaul O, Palcic MM, A PEGA resin for use in the solid phase chcmical/cnzymatic synthesis of glycopeptides, J. Chem. Soc. Chem. Commun., 1849-50, 1994. 

Auzanneau FI, Melda M, Bock K, Synthesis, characterization and biocompatibility of PEGA resins, J. Pept. Sci., 1 31-44, 1995. 

Aggarwal et al. (31) synthesized a random one-bead one-dimer peptide library on a polyethylene glycol acrylamide (PEGA) resin by modifying the one-bead one-compound method and screened the library with a prostate cancer cell line LNCaP. One peptide, QMARIPKRLARH, was found to bind as a dimer to LNCaP cells that had been spiked into the blood, but it did not bind to normal hematopoietic cells. 

In addition to the binding assay, functional assays have been developed for the screening of OBOC libraries to identify specific substrates for protein kinases and proteases. Highly porous PEGA resin is used for the peptide library construction... 

Figure 7 Chemoenzymatic synthesis of macroiactams cataiyzed by Tyc TE. The excised Tyc TE is capabie to produce tyrocidine A (14) with the linear decapeptide NAC thioester or PEGA resin (in blue) with a biomimetic linker. Tyc TE tolerates various modifications to the residues in the rectangle box. However, o-Phe, i-Orn, and i-Leu (in red) are required in all substrates. With modified substrates, Tyc TE generates both macrocyclic peptides with 6-14 amino acids and tyrocidine analogues with different sugar moieties attached to position 4, 5, 6, and 7.

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