Papain Catalyzed (co)Oligomerization of α-Amino Acids

Abstract

Four hydrophobic amino acids (Leu, Tyr, Phe, Trp) were oligomerized by the protease papain in homo-oligomerization, binary co-oligomerization and ternary co-oligomerization. After 24 h, solid polydisperse reaction products of the homo-oligomerization were obtained in yields ranging from 30-80% by weight. A DP avg was calculated based on MALDI-ToF MS results using the ion counts for the chains in the product. Based on the DP avg and the yield of the homo-oligomerization it was determined that the amino acids can be ranked according to reactivity in the order: Tyr > Leu > Phe > Trp. Thermal degradation of the homo-oligomers shows two degradation steps: at 178-239 °C and at 300-330 °C. All the products left a significant amount of char ranging from 18-57% by weight at 800 °C. Binary co-oligomers were obtained as a polydisperse precipitate with a compositional distribution of the chains. Both the compositional and chain length distribution are calculated from MALDI-ToF mass spectra. By comparing the amount of each amino acid present in the chains it was determined that the amino acids are incorporated with a preference: Leu > Tyr > Phe > Trp. Ternary co-oligomers were also obtained as a precipitate and analyzed by MALDI-ToF MS. The compositional distribution and the chain length distribution were calculated from the MALDI-ToF data. The quantity of every amino acid in the chains was determined. Also determined was the influence on the DP avg when the oligomers were compared with corresponding binary co-oligomers. From the combined results it was concluded that in the co-oligomerization of three amino acids the reactivity preference is Leu > Tyr > Phe > Trp. OPEN ACCESSPolymers 2012, 4 711Thermal degradation of all the co-oligomers showed a weight loss of 2 wt% before the main oligomer degradation step at 300-325 °C.

Encapsulation and immobilization of papain in electrospun nanofibrous membranes of PVA cross-linked with glutaraldehyde vapor

“…This protease has been extensively used in traditional food processing applications as a chill-proofing agent: for instance, during beer-finishing operations in the brewing process and also to tenderize meat in the meat industry [3,4]. Papain has been used as a catalyst to oligomerize hydrophobic amino acids [5][6][7][8][9][10][11]. The potential uses of papain include the development of assays and biosensors.…”

Chemoenzymatic Synthesis of Polypeptides for Use as Functional and Structural Materials

“…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…”

“…Methyl, [49,58] ethyl, [44,46,60] isopropyl [23,24] Proteinase I, [49] papain (3.4-6), [58,60] α-chymotrypsin, [23,24] proteinase K (2-7), [44] bromelain (7.5-8.3) [46] l-Threonine…”

“…Ethyl, [49] isopropyl [23,24] Proteinase I, [49] papain (5)(6)(7)(8)(9)(10)(11)(12)(13)(14), [60,67,68] α-chymotrypsin [23,24] l-Lysine…”

Papain, a Plant Enzyme of Biological Importance: A Review

“…Papain is also reported to be used as a surrogate enzyme in a drug design effort to obtain potent and selective inhibitors of cathepsin K, a new member of the papain superfamily of cysteine proteases that is selected and highly expressed in osteoclasts (LaLonde et al, 1998). Papain is also reported to be useful as catalyzed (co) oligomerization of α-amino acids (Schwab et al, 2012).…”