Libraries tags, peptide

Nanokan Easy readout with radiofrequency tags Peptide library is relatively small ... 

More recently, a number of methods have been developed for generating libraries of peptides on resin beads in which each bead is attached to a molecular tag that allows rapid and sensitive identification of the associated polypeptide [108-111]. The tags are attached to the bead coincident with... 

Among the earliest examples of combinatorial libraries were peptide libraries prepared on solid phase via split-mix synthesis. The number of library compounds was high on the other hand, the actually prepared amounts were minute. Therefore, methods to tag each solid-phase bead were developed. 

PNA (see section 1.2.1) has also been used in microarrays a PNA microarray has been used for SNP detection to genotype tomato species/ and with a DNA array where a PNA-tagged peptide library was developed to identify novel cell surface receptor ligands. PNA has been modified with glycan fragments, using the PNA as a barcode for identification of the glycans. ... 

TES-32 is the most abundant single protein product secreted by the parasite. It is also heavily labelled by surface iodination of live larvae (Maizels et al., 1984, 1987), and is known by monoclonal antibody reactivity to be expressed in the cuticular matrix of the larval parasite (Page et al, 1992a). TES-32 was cloned by matching peptide sequence derived from gel-purified protein to an expressed sequence tag (EST) dataset of randomly selected clones from a larval cDNA library (Loukas et al., 1999). Because of the high level of expression of TES-32 mRNA, clones encoding this protein were repeatedly sequenced and deposited in the dataset (Tetteh et al., 1999). Full sequence determination showed a major domain with similarity to mammalian C-type (calcium-dependent) lectins (C-TLs), together with shorter N-terminal tracts rich in cysteine and threonine residues. Native TES-32 was then shown to bind to immobilized monosaccharides in a calcium-dependent manner (Loukas et al., 1999). 

Martin, L.J., Sculimbrene, B.R., Nitz, M., and Imperial/ B. (2005) Rapid combinatorial screening of peptide libraries for the selection of lanthanide-binding tags (LBTs). QSAR Combin. Sci. 24(10), 1149-1157. 

For reduction of resin 8, concerns about the possibility of traces of tin by-products contaminating subsequent assays led to the adoption of a different reduction procedure for library production.15 The tagged resins 8 are combined into one pool in a large peptide synthesis vessel, washed with methanol, filtered, and the resin left solvated. Separately, an aqueous solution of 0.5 M aqueous sodium hydrosulfite/0.5 M potassium carbonate is prepared and added to the resin (40ml/g of resin) and then the resin/solu-tion is bubbled with nitrogen at room temperature for 16 h. The resulting resin is washed with water, water/MeOH (1 1), MeOH, MeOH/NMP (1 1), NMP, DCM, MeOH, and ether, then filtered and dried overnight in vacuo prior to the next step. 

In Section II.C we will present novel tricyclic xanthene derived amino acid templates, which allow the construction of libraries of cyclic conformationally constrained peptide loop mimetics using the split-and-mix method without having to use tagging and deconvolution strategies. In Section III we will focus on parallel and combinatorial approaches devoted to the synthesis of small molecule, non-peptidic compound collections, which in addition offer the possibility to incorporate structural features derived from protein epitope mapping into conformationally constrained peptide mimetics. 

A second paradigm for deconvolution is through libraries based on an encoded bead method (Fig. 6). In this method a readable chemical tag was simultaneously attached to the individual bead for each step in the synthesis of the actual molecule on the bead [66], Herein the library is based on a one-bead-one-compound method, and the activity is measured for individual beads. This determination of activity can be while the test compound is still attached to the bead, where the tag is read directly after the activity is measured. Alternatively, the test compound is cleaved from the bead in a manner that, once activity is detected, allows one to directly return to the individual bead in order to read the tag. The original research in this area was done by Lam and co-workers [14,67, 68], These efforts have progressed to the issuance of a U.S. patent on the one-bead-one-compound methodology with claims for peptide libraries [69], The consequences of the appearance of this patent to those using one-bead-one-compound methods are undetermined at this time. 

Molecular tags overcome the chemical sensitivity and orthogonal protection required by both peptide and oligonucleotide encoding. Two such methods have been developed and applied to the synthesis of both peptide and nonoligomeric libraries. One of these [34] approaches uses chemically robust haloaromatic tags which are used in a binary encoding... 

The encoding tags are halophenoxy derivatives of aliphatic alcohols and are attached to either a photolabile linker as a carbonate or an oxidatively cleavable linker as an ether. The photolabile linker/tag complex is especially well suited to encode peptide libraries through attachment to approximately 1% of the amino groups of each amino acid synthon at eachstage of the synthesis. For structure determination, the tags are released by photolysis at 360 nM. 

As a model enrichment, Doi and Yanagawa (1999) selected for Ni-NTA binders from a library of decamer peptides. The reported enrichment factor for the his-tag fused to streptavidin was, however, only ten. This is probably due to the low efficiency of the protein DNA fusion formation, which was estimated to be only 1%. 

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