Sulforaphane interaction with amyloid beta 1‐40 peptide studied by electrospray ionization mass spectrometry

Abstract

The interaction of SFN, an anticancer agent, with Aβ was studied using ESI-MS. SFN is found to bind covalently and specifically with the free NH(2) group of N-terminal aspartic acid and the ε-amino group of lysine at positions 16 and 28. Aggregation assay studies showed a lesser inclination of Aβ to aggregate when SFN is present. Hence the present study helps in understanding the mechanism of the action of SFN on the Aβ peptide.

Insights into the binding sites of sulforaphane on insulin studied by electrospray ionization mass spectrometry

“…However, when cysteines are free, SFN prefers cysteine SH over the N‐terminus. Unlike our earlier study with Aβ, the lysine of the insulin B chain was not attacked by SFN. Further, SFN did not react with either the phenolic group of tyrosine or the hydroxyl group of serine of insulin.…”

“…(SFN) 2 was 6084.6867 with an error of 3.6 ppm (exact mass 6084.6646). Based on the literature reports and our previous study with amyloid β peptide, [25] it is well known that the SFN binds covalently with proteins. We have carried out LC/MS analysis of the solution to confirm the SFN-binding sites of insulin.…”

“…When cysteines are not freely available (present as disulfide bonds) then SFN binds to an amino group. In our earlier study on SFN interaction with Aβ 1-40 peptide (Aβ), [25] it was found that SFN bound with N-terminal and amine group containing amino acids because the Aβ peptide does not have any cysteine groups.…”

“…Recently, we have reported the interactions of SFN with amyloid β 1–40 peptide . It was found that SFN bound mainly with the N‐terminal and amino group of lysine at the 16 and 28 positions of the amyloid peptide.…”

Pre-Clinical Neuroprotective Evidences and Plausible Mechanisms of Sulforaphane in Alzheimer’s Disease

“…(2) formed three different [Aβ+sulforaphane] complexes due to covalent binding of sulforaphane to Aβ at three different sites (3) sulforaphane bound to free NH 2 groups (N-terminal amino acid and lysines) in Aβ [49] sulforaphane and BACE1 analyzed by fluorescence resonance energy transfer:…”