Perspectives for Photocatalytic Decomposition of Environmental Pollutants on Photoactive Particles of Soil Minerals.

The literature shows that both in laboratory and in industrial conditions, the photocatalytic oxidation method copes quite well with degradation of most environmental toxins and pathogenic microorganisms. However, the effective utilization of photocatalytic processes for environmental decontamination and disinfection requires significant technological advancement in both the area of semiconductor material synthesis and its application. Here, we focused on the presence and "photocatalytic capability" of photocatalysts among soil minerals and their potential contributions to the environmental decontamination in vitro and in vivo. Reactions caused by sunlight on the soil surface are involved in its normal redox activity, taking part also in the soil decontamination. However, their importance for decontamination in vivo cannot be overstated, due to the diversity of soils on the Earth, which is caused by the environmental conditions, such as climate, parent material, relief, vegetation, etc. The sunlight-induced reactions are just a part of complicated soil chemistry processes dependent on a plethora of environmental determinates. The multiplicity of affecting factors, which we tried to sketch from the perspective of chemists and environmental scientists, makes us rather skeptical about the effectiveness of the photocatalytic decontamination in vivo. On the other hand, there is a huge potential of the soils as the alternative and probably cheaper source of useful photocatalytic materials of unique properties. In our opinion, establishing collaboration between experts from different disciplines is the most crucial opportunity, as well as a challenge, for the advancement of photocatalysis.

Peptides accompanying chicken egg yolk IgY--alternative methods of isolation and immunoregulatory activity.

In the hen immune system the egg content plays as significant a role in the development of the chick as colostrum does in newborn mammals. One of the most important proteins in this system seems to be the main yolk immunoglobulin IgY. It has been shown that IgY is accompanied by an immunostimulatory polypeptide complex named yolkin. In this report the biological activities of yolkin separated by means of four different procedures are presented. It was shown that yolkin acts as an inducer rather than a modulator of cytokine and nitric oxide release, and does not participate in the protection of cells against destructive effects of reactive oxygen species. However, using the perchloric acid procedure it is possible to obtain a peptide fraction with higher inducing activity, stronger antioxidant properties and ability to decrease the NO level induced by lipopolysaccharide. The results obtained show that it is feasible to select one of the presented methods of yolkin isolation that yields a product of particular activity. The properties of yolk peptides not only indicate their roles in the development of chicks, but can also be useful for the regulation of some immunological disturbances.

Immunologically active peptides that accompany hen egg yolk immunoglobulin Y: separation and identification.

The protein mixture of cytokine-inducing activity accompanying chicken immunoglobulin Y, named yolkin, consists of several peptides of molecular weight (MW) ranging from over 1 to 35 kDa. Yolkin and its constituent peptides were found to be efficient inducers of interleukin (IL)-1ß, IL-6 and IL-10 secretion. N-terminal amino acid sequences of eight of the electrophoretically purified yolkin constituents revealed that all of them are homological to some fragments of the C-terminal domain of vitellogenin II. The fractions of MW about 4 and 12 kDa are free of carbohydrates and start at position 1732 in the vitellogenin amino acid sequence; whereas the other fractions (MW about 16, 19, 23, 29, 32 and 35 kDa) appeared to be glycoproteins corresponding to the amino acid sequence of vitellogenin starting at position 1572. From these data, it is concluded that yolkin most likely represents vitellogenin-derived peptides that possess cytokine-inducing activity and are, at least partially, responsible for such properties of separated immunoglobulin Y preparation. This finding reveals a new role for vitellogenin as a reservoir of polypeptides that may play an important role in the innate immune system of the developing embryo.