Synthesis of peptides with narrow molecular weight distributions via exopeptidase-catalyzed aminolysis of hydrophobic amino-acid alkyl esters

Abstract

A new synthesis technique that produces homogeneous oligopeptides that are essential for the formation of self-assembled structures is described. In contrast with endopeptidases, exopeptidases, which catalyze the cleavage of terminal peptide bonds, can potentially prevent unexpected hydrolysis during aminolysis. This is the first report on exopeptidase-catalyzed oligopeptide synthesis. Oligo(L-leucine) was synthesized using the exopeptidase carboxypeptidase Y (CPDY), which also prevented enzymatic hydrolysis. A high yield of oligo(L-leucine) with a narrow polydispersity (PDI) was obtained by limiting polypeptide cleavage during aminolysis. The reaction conditions, such as the temperature, pH, CPDY and substrate concentrations, were optimized to produce the best yields, molecular weights and PDI of the oligomers. Hydrophobic L-leucine methyl ester and L-isoleucine methyl ester were found to be the appropriate substrates for CPDY-catalyzed oligomerization; however, no oligomers were obtained using hydrophilic amino-acid esters. Oligomer yields were also affected by the amino-acid ester groups. Remarkably, the PDI of the oligomers was as low as 1.0, regardless of the reaction conditions and types of substrates used. Thus, exopeptidase-catalyzed oligomerization may become an alternative route for the current endopeptide-catalyzed oligomerization of peptides.

Effects of washing and membrane removal pretreatments on the antioxidant properties of grass carp (Ctenopharyngodon idella) protein hydrolysates produced by in vitro digestion

“…M P , Peak molecular weight; M W , Weight‐average molecular weight; M N , Number‐average molecular weight; PDI, polydispersity index, which was used as a measure of the broadness of a molecular weight distribution of the hydrolysate (Garcia et al ., ; Nitta et al ., ). A larger PDI means there was a wider distribution of molecular weights, the uniform distribution of molecular weight has an M W / M N = 1.…”

Chemoenzymatic Synthesis of Polypeptides for Use as Functional and Structural Materials

“…For example, carboxypeptidase Y (CPDY) was successfully utilized for the chemoenzymatic synthesis of poly(l-leucine) (polyLeu) with a relatively narrow molecular weight distribution. [63] All of the proteases described above are endopeptidases and digest amide bonds within the polypeptide backbone. In contrast, CPDY is characterized as an exopeptidase that typically cleaves only amide bonds at C-termini.…”

“…Methyl, [57,58,63] ethyl [46,49,52,56,62] Proteinase I, [49] papain (4)(5)(6)(7)(8)(9)(10)(11)(12), [46,52,[56][57][58][59][60]62] bromelain (6.5-7.9), [46,59] α-chymotrypsin (8.2-9.4), [46,59,61] protease SG (8.5), [59] CPDY (6) [63] l-Isoleucine…”

Synthetic Approach of Thermally Tunable Nature‐Mimetic Polypeptides from N‐Protected Alternating Peptoids

“…Fibroin, collagen, and elastin are the representative members of structural proteins, which exhibit fibrous functions. Therefore, the practical synthetic methods for polypeptides consisting of a repeating sequence have been extensively studied as a key technique for the creation of new peptide‐based materials . An alternating peptide is the simplest class in such regularly arranged polypeptides.…”

“…Therefore, the practical synthetic methods for polypeptides consisting of a repeating sequence have been extensively studied as a key technique for the creation of new peptide-based materials. [8][9][10] An alternating peptide is the simplest class in such regularly arranged polypeptides. The polymer alternately includes two kinds of amino acid skeletons in the main chain.…”