Mass spectral and theoretical investigations of the transient proton-bound dimers on the cleavage processes of the peptide GHK and its analogues.

ABSTRACT: Fragmentation mechanisms of the singly protonated peptides GHK, GHKH and HGHK have been investigated by mass spectrometry and theoretical calculations. Fragmentation behavior of the protonated H-K amide bond in GHK was changed completely when a histidinyl residue was introduced into the C-terminus of GHK. The H-K amide bond breaking was a predominant pathway in the case of GHK and GHKH. For HGHK, the histidinyl residue at the N-terminus hampered significantly breaking of the H-K amide bond resulting in a high potential energy barrier; calculations indicated that this histidinyl effect played a vital role for the H-K amide bond fragmentation. Subsequent analysis of the fragmentation mechanism revealed that recombination processes of the hydrogen bonding for the intermediate products were al

SUBMITTER: Wang J 

PROVIDER: S-EPMC8694339 | biostudies-literature | 2021 Jan

REPOSITORIES: biostudies-literature