Evidence for a conformational polymorphism of invertebrate neurohormones. D-amino acid residue in crustacean hyperglycemic peptides

Mass spectrometric differentiation of linear peptides composed of L-amino acids from isomers containing one D-amino acid residue.

MS/MS of electrosprayed ions is shown to have the capacity to discriminate between peptides that differ by configuration about their alpha-carbons. It is not necessary for the peptides to possess tertiary structures that are affected by stereochemistry, since five epimers of the pentapeptide, H2N-Gly-Leu-Ser-Phe-Ala-OH (GLSFA) all display different collisionally activated dissociation (CAD) pat...

Effect of a glycine residue insertion into crustacean hyperglycemic hormone on hormonal activity.

Crustacean hyperglycemic hormone (CHH) and molt-inhibiting hormone (MIH) have similar amino acid sequences and therefore comprise a peptide family referred to as the CHH family. All MIHs unexceptionally have an additional glycine residue at position 12, which is lacking in all CHHs. In order to understand the relevance of the absence of the glycine residue for hyperglycemic activity, a mutant C...

Peptides containing a D-amino acid from frogs and molluscs.

D-amino acid residues in peptides and proteins.

We have investigated the D-amino acid residues present in Protein Data Bank (PDB) entries, categorizing them into "real" D-residues and artifacts. In polypeptide chains of more than 20 residues, only a single instance of a "real" D-residue, other than those deliberately designed or engineered, was found. This example was the result of a slow chemical epimerization process. Another 12 designed D...

D-amino acid-containing peptides in Conus venoms

-amino acids have been documented in relatively few gene products, including peptides found in Conus venoms. The present work provides an overview of various D-amino acid-containing Conus peptides (conopeptides or conotoxins), such as the contryphans, conomarphins, conophans, conomap and certain I1-superfamily conotoxins. Characterization of their sequences and structures, as well as the known ...