Peptides preparation

TABLE 5-3. Peptides prepared with NJf -carbonylbis(3-methylimidazolium) triflate. Peptides prepared with Peptides prepared with... 

TABLE 5-4 Peptides prepared with other imidazolides and triazolides. 

Both collisional activation (in ion traps) and post source decay (in curved field reflectron TOF analyzers) have been used successfully to obtain sequence ions from peptides prepared in situ on the sample holder. Single Dalton mass windows are advantageous for precursor selection, as are realized in ion-trap and trap-TOF configurations. Publicly available search algorithms can be used... 

Figure 12.4 MALDI analysis of peptides prepared in situ from a 10 1 mixture of Bacillus cereus and Bacillus anthracis sp. Sterne.82 (a) Survey spectrum of peptide products. Species assignments are indicated on the figure. (b) Spectrum of fragment ions produced by low-energy collisions of the Bacillus cereus-specific peptide of mass 1529. (c) Spectrum of fragment ions produced by low-energy collisions of ions of the Bacillus anthracis peptide of mass 1528.

One of the cornerstones of combinatorial synthesis has been the development of solid-phase organic synthesis (SPOS) based on the original Merrifield method for peptide preparation [19]. Because transformations on insoluble polymer supports should enable chemical reactions to be driven to completion and enable simple product purification by filtration, combinatorial chemistry has been primarily performed by SPOS [19-23], Nonetheless, solid-phase synthesis has several shortcomings, because of the nature of heterogeneous reaction conditions. Nonlinear kinetic behavior, slow reaction, solvation problems, and degradation of the polymer support, because of the long reactions, are some of the problems typically experienced in SPOS. It is, therefore, not surprising that the first applications of microwave-assisted solid-phase synthesis were reported as early 1992 [24],... 

HC1 (18°C), recovery by rotary evaporation, and electrolytic reduction. Once isolated, the free dipetide ester (or acid) is available for chain lengthening (cf. Scheme 1) and Table VII gives examples of peptides prepared using this approach. 

Figure 1.5 Disulfide-containing receptors for peptides prepared by Hioki and Still.

Table 2 A Selection of Tyr(P)-Peptides Prepared Using Fmoc-Tyr[PO(OMe)2]-OH mQ °- 321...

Table 5 Phe[CF2PO(OH)2]-Peptides Prepared Using Boc/Fmoc-Phe[CF2PO(OEt)2]-OH and Fmoc-Phe[CF2PO(OH)2]-OH Derivatives 59-61-63-671...

Table 6 Ser(P)- and Thr(P)-Peptides Prepared Using Fmoc-Ser[PO(OBzl)(OH)]-OH and Fmoc-Thr[PO(OBzl)(OH)]-OH[26-48-84 )2 )3l...

Results comparable to those shown in Figure 1 can readily be achieved with most crude mixtures containing synthetic or naturally occurring peptides, using similar RPC strategies. The resolution of synthetic peptides prepared by solid- or solution-phase chemical methods is now so routine by analytical and preparative RPC methods that an April 2000 CD-ROM database search of relevant scientific journals revealed that over 2500 publications arise each year on the use of RPC for the purification or analysis of peptides as part of the scientific literature related to peptide chemistry and its application in various fields of the biomedical or biological science and in biotechnological applications related to the food, environmental, and pharmaceutical industries. 

FAB peptide preparation is accomplished by dissolving a relatively pure (>70%) peptide sample into a 3-nitrobenzyl alcohol (NBA) matrix. There are many matrices used in FAB analyses, however, 3-nitrobenzyl alcohol has become a standard for FAB peptide analysis (Figure 12). The peaks associated with the NBA matrix can make the spectra more cumbersome to interpret. However, to the experienced mass spectroscopist the matrix ions can act as reference ions and are a useful indicator of accuracy. Rarely are the NBA matrix ions observed above m/z 1000. 

Kessaissia, S., Siffert, B., and Donnet, J. B. (1980). Synthese de peptides preparation de I acide hippurique par reaction des complexes montmorillonite-glycine avec I acide benzoique. Clay Minerals, 15, 383-92. 

Tsuge, N., Eikawa, Y., Nomura, Y., Yamamoto, M., and Sugisawa, K. (1991). Antioxidative activity of peptides prepared by enzymatic hydrolysis of egg-white albumin. Nippon Nogeikagaku Kaishi 65,1635-1641. 

Hsu, . C., Li-Chan, E. C. Y., and Jao, C. L. (2011). Antiproliferative activity of peptides prepared from enzymatic hydrolysates of tuna dark muscle on human breast cancer cell line MCF-7. Food Chem. 126, 617-622. 

Asymmetric parallel P-sheet sequences incorporating template 4 (R1 = H) were synthesized on BHA resin and reacted with the bifunctional electrophile 4 (R1=Pfp). The remaining active ester on the template-terminated resin-bound peptide was reacted with the N-terminus of a different side-chain protected peptide prepared on the oxime resin, as shown in Scheme 11. 

Weetall 1111 (ed) (1975) Immobilized enzymes, antigens, antibodies and peptides - preparation and characterization. Dekker, New York... 

Nakagawa, H., Ishihara, M., and Ohashi, K (1993). 33-kDa peptides prepared from chicken gizzard smooth muscle bundle both actin and desmin filaments in vitro. J. Biochem. (Tokyo) 114, 623-626. 

FIGURE 9.11 Amino acid sequence of modified peptides prepared by chemists at Miracles... 

Frank, R. and Overwin, H. (1996) SPOT synthesis. Epitope analysis with arrays of synthetic peptides prepared on cellulose membranes. In Epitope Mapping Protocols, ed. G.E. Morris, pp. 149-169. Totowa, NJ Humana Press. 

Asakura, T., Suita, K., Kameda, T., Afonin, S., and Ulrich, A.S. "Structural role of tyrosine in Bombyx mori silk fibroin, studied by solid-state NMR and molecular mechanics on a model peptide prepared as silk I and II". Magn. Reson. Chem. 42(2), 258-266 (2004). 

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