Anti-Melanoma monoclonal antibody, clone QOM3

Presented here are the results of a study characterizing the selective metal chelating performance of the alternative metal binding (amb) peptide: acetyl-His(1)-Cys(2)-Gly(3)-Pro(4)-His(5)-Cys(6)-OH, and eight ambs with systematic modifications to His, Cys, and carboxyl C-terminus metal chelating sites. The results show that from the divalent metal ions of zinc, nickel, cobalt, magnesium and calcium, the ambs most extensively formed complexes with zinc and nickel. The ambs, which retained both Cys(2) and Cys(6) in their primary structure, exhibited the greatest formation of zinc complexes. The replacement of His(1) and His(5) residues with two additional Cys with the amidation of the C-terminus also increased the zinc chelation at pH 7.0. Density functional theory indicated that these modifications might be disrupting the hydrogen bonding between the His-Cys and carboxylate terminus making the 4Cys more available for chelation. Nickel chelation was generally lower than zinc because of competition from the Cys to form disulfide bonds in the presence of nickel. The two ambs that formed the highest number of nickel complexes both included the amidated C-termini and either 4Cys or 2Cys-2His. Comparison with recent published results of six heptapeptide ambs, which have the same primary structures, but with the inclusion of Tyr(5) before the final two residues, indicates the inclusion of the Tyr(5) residue increases the zinc chelation at pH 7.0 from 25%, of total observed species, to 70%. These types of studies may pave the way to discoveries of new therapeutics suitable as enzyme inhibitors or chelators for diseases associated with metal homeostasis misbalances, or as new peptide tags for recombinant protein purification. (C) 2020 Elsevier B.V. All rights reserved.

To better understand the contribution of myosin light chain (MLC) isoforms to sensory defects in Jinhua ham, dipeptidyl peptidase (DPP) activities, peptide fragments, cleavage sites and the potential of DPP to develop sensory defects of dry-cured ham were evaluated and discussed in normal and defective hams. Higher residual activities of DPP I were found in defective ham compared with normal ham; approximate 3-fold peptide fragments were identified in defective ham than in normal ham. These regions of positions 11-35 and 116-141 in MLC 1, 13-53 and 139-156 in MLC 2, and 18-50 in MLC 3 contributed to the intense generation of peptide fragments in defective ham. PLS-DA further revealed DPP I showing intense response to degrade peptides. Cleavage sites including Glu-128, Tyr-132 and Glu-133 were responsible for the intense release of dipeptides in defective ham. These cleavages could play key role in discriminating taste attributes between defective and normal hams.