Investigations on the characteristics of BSA-lipid oxidation product
interactions: role of three dien-aldehyde with different chain lengths
Abstract
Protein modification by aldehydes has been generally associated with
aging and onset of various chronic and cardiovascular diseases. The
characteristics of bovine serum albumin (BSA) incubated with three
dien-aldehydes (trans, trans-2,4-heptadienal, trans,
trans-2,4-nonadienal, trans, trans-2,4-decadienal) of different chain
lengths at different concentrations were examined. The results were as
follows: loss of the amino group and increased carbonyl value were
indicative of BSA side chain damage by these three unsaturated
aldehydes. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis
results showed that all the three aldehydes led to formation of BSA
aggregation; the most significant effect was observed for heptadienal.
Changes in intrinsic fluorescence and surface hydrophobic value of BSAs
indicated that aldehydes modified protein structures of BSAs. Moreover,
the three aldehydes used in this experiment caused BSAs to form
yellowish-brown adducts and fluorescent lipofuscin. The heptadienal-BSA
adducts exhibited increased ultraviolet–visible (UV-Vis) absorbance at
270-280 nm and 300-400 nm, similar to the two other aldehyde-BSA
adducts. We also examined the correlation between the various oxidation
parameters and the concentration of modifiers. Strong correlations were
observed between formation of protein-bound carbonyls, the retention
ratio of free amino content, maximum UV-Vis absorption value, and
concentration of aldehydes. Finally, Principal component analysis (PCA)
analysis was conducted on oxidation parameters and the comprehensive
effect of these parameters on BSA modification. In general, greater BSA
damage was observed when incubated with aldehydes with shorter chain
length at higher concentration.