Systemic lupus erythematosus (SLE) is an inflammatory, autoimmune disorder of unknown etiology. The inflammatory stress in SLE patients may modify macromolecules and produce structural/functional abnormalities. The present study is aimed at examining the consequences of stresses on the structure of
albumin in SLE patients.
Albumin was isolated from the sera of SLE/healthy subjects. Multiple physicochemical techniques were used to elucidate, structure of
albumin.
Advanced glycation end products in SLE patients'
albumin were identified by the AGE specific fluorescence. Quenching of
tryptophan,
tyrosine fluorescence and
surface protein hydrophobicity was observed in SLE patients'
albumin.
Protein-bound carbonyls were elevated while free
thiol,
lysine,
arginine, and alpha helicity was found to be decreased in SLE
albumin. Furthermore, changes in the secondary structure of SLE
albumin were observed as shift in the position of
amide I/II bands. Functionality of SLE
albumin was also compromised as its
cobalt-binding ability was substantially declined. Adduction of moieties was detected by dynamic light scattering (DLS) and confirmed by matrix assisted
laser desorption/ionization. DLS,
thioflavin T and transmission electron microscopy results confirmed aggregates in SLE patients'
albumin. This study may be helpful in understanding the role of modified
albumin in the cofounding pathologies associated with SLE.