Peptide length distribution

As shown below, the presence of a second cleavage centre does not significantly change the results. Hence, to find the conditions for a maximum in the peptide length distribution, we use the analytical expressions for the case of one cleavage center. This peptide length distribution has extrema at the points where ... 

As predicted by theory (solid line) the numerically computed peptide length distribution (denoted by boxes) has a maximum for one cleavage center (b), two cleavage centers with immediate disappearance of cleavage products (c), and in the case where the cleavage products do not disappear (d). 

The stationary solution of Eq. (12) with the boundary condition Eq. (13) gives the asymptotic distribution of protein coordinates which coincides with the length distribution of peptides p(x) (because probability of a strand to be cut is independent of its coordinate). The problem in Eqs. (12), (13) admits the stationary solution ... 

In the 1980s, Julia and Colonna discovered that the Weitz-Scheffer epoxidation of enones such as chalcone (4, Scheme 2) by alkaline hydrogen peroxide is catalyzed in a highly enantioselective fashion by poly-amino acids such as poly-alanine or poly-leucine (Julia et al. 1980, 1982). The poly-amino acids used for the Julia-Colonna epoxidation are statistical mixtures, the maximum length distribution being around 20-25 mers (Roberts et al. 1997). The most fundamental question to be addressed refers to the minimal structural element (i.e. the minimal peptide length) required for catalytic activity and enantioselectiv-ity. To tackle this question, we have synthesized the whole series of L-leucine oligomers from 1- to 20-mer on a solid support (Berkessel... 

Fig. 22.1. H 0 hydrogen-bond length distributions in carbohydrate, purine, pyrimidine, nucleoside, nucleotide and peptide hydrates. Note that OH - Ow

Abstract This article summarizes recent developments in the synthesis of polypeptides and hybrid peptide copolymers. Traditional methods used to polymerize -amino acid-N-carboxyanhydrides (NCAs) are described, and limitations in the utility of these systems for the preparation of polypeptides are discussed. Recently developed initiators and methods are also discussed that allow polypeptide synthesis with good control over chain length, chain length distribution, and chain-end functionality. The latter feature is particularly useful for the preparation of polypeptide hybrid copolymers. The methods and strategies for the preparation of such hybrid copolymers are described, as well as analysis of the synthetic scope of the different methods. Finally, issues relating to obtaining these highly functional copolymers in pure form are detailed. 

Synthetic peptides have been extensively used to study the thermal stability and folding of the triple helix. These peptides can be synthesized as either single chains or cross-linked peptides. Early on, such peptides were synthesized by polycondensation of tri- or hexapeptides, which led to a broad mass distribution that was difficult to separate. With the advances of solid-phase synthesis methods, peptides with defined chain length became available. The most studied collagen-like peptides are (Gly-Pro-Pro) or (Pro-Pro-Gly) and (Gly-Pro-4(if)Hyp) or (Pro-4(if)Hyp-Gly) with n varying from 5 to 15. Sutoh and Noda" " introduced the concept... 

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