Structural analysis of a natural apolipoprotein A-I variant (L60R) associated with amyloidosis.

The reason that determines the pathological deposition of human apolipoprotein A-I variants inducing organ failure has been under research since the early description of natural mutations in patients. To shed light into the events associated with protein aggregation, we studied the structural perturbations that may occur in the natural variant that shows a substitution of a Leucine by an Arginine in position 60 (L60R). Circular dichroism, intrinsic fluorescence measurements, and proteolysis analysis indicated that L60R was more unstable, more sensitive to cleavage and the N-terminus was more disorganized than the protein with the native sequence (Wt).

Application of hydrogen peroxide to the control of eutrophic lake systems in laboratory assays.

We exposed water samples from a recreational lake dominated by the cyanobacterium Planktothrix agardhii to different concentrations of hydrogen peroxide (H2O2). An addition of 0.33 mg·L-1 of H2O2 was the lowest effective dose for the decay of chlorophyll-a concentration to half of the original in 14 h with light and 17 h in experiments without light.