Accelerated removal of deamidated proteins and endogenous electric fields: possible implications.
Changes in protein structure through the spontaneous deamidation of asparaginyl (Asn) and glutaminyl (Gln) residues have been observed in many proteins. Amide residues were supposed to serve as clocks for development and aging. Deamidated proteins are rapidly degraded by as yet unclear molecular mechanisms. Deamidation leads to elevation of the ratio of charged versus polar residues (CH-PO) of a protein and to a decrease in its pI value. We had reported that those enzymes, characterized by a high CH-PO, are prone to inactivation and loss of ordered structure by exposure to direct current from low voltage in solution. Nano-local endogenous electric fields arise within cells. Endogenous currents may cause the unfolding of the products of deamidation at Asn. In turn, these unfolded proteins would be removed, likely by proteolysis.
Panfoli
Isabella
I
Department of Biology, University of Genova, 16132 Genova, Italy. Isabella.Panfoli@unige.it
Ravera
Silvia
S
Calzia
Daniela
D
Morelli
Alessandro
A
D000375:Aging / Q000378:metabolism; D001216:Asparagine / Q000737:chemistry; D055592:Biophysical Phenomena; D004560:Electricity / Q000009:adverse effects*; D005973:Glutamine / Q000737:chemistry; D007526:Isoelectric Point; D008954:Models, Biological; D010447:Peptide Hydrolases / Q000378:metabolism; D017510:Protein Folding; D011506:Proteins / Q000737:chemistry* / Q000378:metabolism*
D011506:Proteins; D005973:Glutamine; D001216:Asparagine; D010447:Peptide Hydrolases