Edman degradation supports

The Ugi reaction is, for instance, used for the immobilization of enzymes, and it is one of the best methods for attaching peptide and protein molecules to a solid support for sequence analysis by a modified Edman degradation. - ... 

Modified or unusual amino acids such as hydroxyproline and phos-phoserine and protected amino acids can also be identified by Edman degradation sequence analysis [38], However, it is important to remember that in this method, identification of a residue is made solely on the basis of HPLC retention time. It is, therefore, essential to support the identification of a modified residue by comparison with authentic standards. Furthermore,... 

An example of a reaction on a solid-phase matrix, the Merrifield resin, is shown in Fig. 7.14. The peptide fragments are covalently bonded, either onto a poiymer membrane or onto micrometer sized beads. The solid support is then immersed into a liquid phase and Edman degradation is carried out by sequentially adding the required reagents and removing the products for analysis. 

CPA is often used for sequencing protein samples. Whereas there is an effective way to sequence from the amino terminus, such as with Edman degradation with phenyl isothiocyanate, there are few such methods for sequencing from the carboxyl terminus (hyclrazinolysis is one such chemical method). Hence, digestion with CPA is a choice whe e one needs to know the amino acid sequence from the C-terminus. The time course of amino acid release is monitored on the amino acid analyzer. This way to use CPA seems to be made even more effective by immobilizing it on a solid support. Bovine enzyine was... 

This state has to be attained particularly at the end of the synthesis, before the detachment of the peptide should be performed. A sample of the polymer-supported end product should be analyzed by quantitatively exploitable Edman degradation to determine the quality of the synthesis before cleavage as described on p. 60. 

Because of this uncertainly, we try, first, to control the course of the synthesis as completely as possible during its processing. Second, we try to determine the quality of the synthetic end product on polymer by the aid of Edman degradation with quantitative exploitation of the phenylthiohydantoines obtained [161,164]. In this way contaminations of the product by false sequences can be detected in relative amounts of as small as 0.1% of the main chain. Generally we experienced purer peptides synthesized than liberated from polymer by any detachment reaction. This can be demonstrated qualitatively by the aid of thin layer chromatograms of the crude peptide products released from the support after the cleavage reaction and by end-group determinations before and after peptide detachment. 

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