Peptide Bond Cleavage through Asparagine Cyclization

Spontaneous peptide bond cleavage in aging alpha-crystallin through a succinimide intermediate.

Cleavage of specific peptide bonds occurs with aging in the alpha A subunit of bovine alpha-crystallin. One of the breaks occurs at residue Asn-101. This same residue undergoes in vivo deamidation, isomerization, and racemization. Deamidation and isomerization are known to occur via succinimide ring formation of labile asparagine residues. Model studies on peptides have shown that imide formati...

Peptide Bond Cleavage on Trypsintrypsin Inhibitor Complex Formation.

Branched Intermediate Formation Stimulates Peptide Bond Cleavage in Protein Splicing

Protein splicing is a post-translational modification in which an intein domain excises itself out of a host protein. Here, we investigate how the steps in the splicing process are coordinated so as to maximize the production of the final splice products and minimize the generation of undesired cleavage products. Our approach has been to prepare a branched intermediate (and analogs thereof) of ...

NBS mediated nitriles synthesis through C=C double bond cleavage.

An NBS mediated nitriles synthesis through C=C double bond cleavage has been developed. TMSN3 was employed as the nitrogen source for this Cu(OAc)2 promoted nitrogenation reaction. This transformation has a relatively high regio-selectivity to form aromatic nitriles.

Optimization of Nonenzymatic Microwave D-Cleavage and Disulfide Bond Cleavage

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...