the zinc(ii) complex [zn2(dmdtc)2(μ-dmdtc)2] has been synthesized directly from thiram ligand, containing a disulfide bond {dmdtc = n,n-dimethyldithiocarbamate; thiram = n,n-tetramethylthiuram disulfide}, and characterized by elemental analysis and spectroscopic methods. surprisingly thiram, undergoes a reductive disulfide bond scission upon reaction with zn2+ in methanolic media to give the [z...

the zinc(ii) complex [zn2(dmdtc)2(μ-dmdtc)2] has been synthesized directly from thiram ligand, containing a disulfide bond {dmdtc = n,n-dimethyldithiocarbamate; thiram = n,n-tetramethylthiuram disulfide}, and characterized by elemental analysis and spectroscopic methods. surprisingly thiram, undergoes a reductive disulfide bond scission upon reaction with zn2+ in methanolic media to give the [z...

The zinc(II) complex [Zn2(dmdtc)2(μ-dmdtc)2] has been synthesized directly from thiram ligand, containing a disulfide bond {dmdtc = N,N-dimethyldithiocarbamate; thiram = N,N-tetramethylthiuram disulfide}, and characterized by elemental analysis and spectroscopic methods. Surprisingly thiram, undergoes a reductive disulfide bond scission upon reaction with Zn2+ in methanolic media to give the [Z...

Radical induced disulfide bond cleavage in peptides was demonstrated by ultraviolet (UV) radiation of the electrospray ionization (ESI) plume using a low pressure mercury (LP-Hg) lamp. Tandem mass spectrometry and accurate mass measurements confirmed that the primary reaction products were due to disulfide bond cleavage to form thiol (-SH) and sulfinyl radical (-SO˙). Mechanistic studies showed...

Disulfide bonds generally show only limited cleavage in positive ion mode collision activated dissociation (CAD). However, it has been emonstrated that a reverse situation exists in negative ion mode in which preferential S S and C S bond cleavage occurs. Here, we show that lectron detachment dissociation (EDD) and infrared multiphoton dissociation (IRMPD) of peptide anions containing disulfide...

Peptide and protein characterization by mass spectrometry (MS) relies on their dissociation in the gas phase into specific fragments whose mass values can be aligned as 'mass ladders' to provide sequence information and to localize possible post-translational modifications. The most common dissociation method involves slow heating of even-electron (M+nH) n+ ions from electrospray ionization by ...

During the last years there was a substantial increase in the use of antibodies and related proteins as therapeutics. The emphasis of the pharmaceutical industry is on IgG1, IgG2, and IgG4 antibodies, which are therefore in the focus of this article. In order to ensure appropriate quality control of such biopharmaceuticals, deep understanding of their chemical degradation pathways and the resul...

Disulfide bonds between the side chains of cysteine residues are the only common crosslinks in proteins. Bovine pancreatic ribonuclease A (RNase A) is a 124-residue enzyme that contains four interweaving disulfide bonds (Cys26-Cys84, Cys40-Cys95, Cys58-Cys110, and Cys65-Cys72) and catalyzes the cleavage of RNA. The contribution of each disulfide bond to the conformational stability and catalyti...

A functional disulfide bond in both the HIV envelope glycoprotein, gp120, and its immune cell receptor, CD4, is involved in viral entry, and compounds that block cleavage of the disulfide bond in these proteins inhibit HIV entry and infection. The disulfide bonds in both proteins are cleaved at the cell surface by the small redox protein, thioredoxin. The target gp120 disulfide and its mechanis...

A nonenzymatic digestion technique allows proteins to be well suited for collision-induced dissociation tandem mass spectrometry. This method utilizes microwaves and Dithiothreitol (DTT) to selectively cleave at aspartic acid (D) and disulfide bonds. This microwave digestion technique is reproducible and produces peptides with a shortened sequence length. Insulin I is used in this study to opti...