A regulatory protein isolated from cattle milk

A regulatory protein displaying biological activity at ultralow doses was identified in cow’s milk. The isoelectric point for this protein falls into the pH range of 4.48–5.59, and the molecular weight does not exceed 10 kDa. A study of the secondary structure detected the predominant presence of β-structures, especially antiparallel, in the molecule of this regulatory protein as well as the regions described in terms of a statistical globule. It was demonstrated that this protein is located extracellularly in the epithelium of mammary ducts, and that this regulatory protein is present in an active form in whole milk; however, it was detectable neither in dry milk nor in infant formula. The results obtained suggest that the milk regulatory protein characterized in this work was identical to low-molecular-weight serum glycoprotein, one of the proteins studied earlier, displaying biological activity at ultralow doses.     

Structural-functional characteristics of a new bioregulator isolated from bovine pigmented epithelium tissue

A new bioregulator operating in ultralow doses corresponding to 10^?17 mg/ml has been isolated from tissue of pigmented epithelium of bovine eyes. It has been established that the functional basis of this bioregulator is a complex of a low molecular weight regulatory peptide (4372 Da) and a modulator consisting of a mixture of proteins with molecular weights of 14.980–66.283 kDa. It has been shown that the regulatory peptide is responsible for membranotropic activity of the bioregulator, and the modulator proteins are responsible for biological action in ultralow doses. The data demonstrate an interrelation between nanocondition of the bioregulator and its ability to show activity in ultralow doses.     

A study of the adhesive glycoprotein-inactivating protein from mammalian blood serum

A protein with a molecular weight of 70 kDa was isolated from bovine blood serum and purified to a homogenous state. This protein inhibited reversibly the adhesive serum glycoprotein with a molecular weight of 12 kDa, which displayed biological activity at ultralow doses. Amino acid analysis showed that the protein inactivator belongs to the group of prealbumins from vertebrate blood serum. The secondary structure of its molecule was characterized by a considerable number of alpha-helices. The conditions for inactivation of serum glycoprotein were studied. The interaction between the serum glycoprotein and the protein inactivator occurred over a long period of time (1 day). It should be emphasized that the presence of calcium ions was a necessary condition for the inactivation of the serum glycoprotein. The data suggest that inactivation of serum glycoprotein results from the formation of a molecular complex consisting of the protein inactivator and the glycoprotein, which is related to the carbon-protein interaction.     

Identification of a new bioregulator acting in ultralow doses in bulb onion (Allium cepa L.)

A bioregulator that has physicochemical and biological properties similar to a group of bioregulators isolated from various animal tissues has been found in the bulb onion (Allium cepa L.). It was determined that the biological action of the plant bioregulator is determined by a peptide with molecular weight of 4036 +/- 2 Da whose 18-C-terminal amino acid sequence consisted of 18 residues. On models of seed germination of some vegetable cultures, the ability of the bioregulator isolated from supernatant of onion extract in ultralow doses (10(-13) mg of protein/ml) to inhibit growth and development was demonstrated.     

A Study of the Adhesive Glycoprotein-Inactivating Protein from Mammalian Blood Serum

A protein with a molecular weight of 70 kDa was isolated from bovine blood serum and purified to a homogenous state. This protein reversibly inhibited the adhesive serum glycoprotein with a molecular weight of 12 kDa, which displayed biological activity at ultralow doses. Amino acid analysis showed that the protein inactivator belongs to the group of prealbumins from vertebrate blood serum. The secondary structure of its molecule was characterized by a considerable number of -helices. The conditions for inactivation of serum glycoprotein were studied. The interaction between the serum glycoprotein and the protein inactivator occurred over a long period of time (1 day). It should be emphasized that the presence of calcium ions was a necessary condition for the inactivation of the serum glycoprotein. The data suggest that inactivation of serum glycoprotein results from the formation of a molecular complex consisting of the protein inactivator and the glycoprotein, which is related to the carbon–protein interaction.     

Milk inhibits the biological activity of ricin

Ricin is a highly toxic protein produced by the castor plant Ricinus communis. The toxin is relatively easy to isolate and can be used as a biological weapon. There is great interest in identifying effective inhibitors for ricin. In this study, we demonstrated by three independent assays that a component of reconstituted powdered milk has a high binding affinity to ricin. We discovered that milk can competitively bind to and reduce the amount of toxin available to asialofetuin type II, which is used as a model to study the binding of ricin to galactose cell-surface receptors. Milk also removes ricin bound to the microtiter plate. In parallel experiments, we demonstrated by activity assay and by immuno-PCR that milk can bind competitively to 1 ng/ml ricin, reducing the amount of toxin uptake by the cells, and thus inhibit the biological activity of ricin. The inhibitory effect of milk on ricin activity in Vero cells was at the same level as by anti-ricin antibodies. We also found that (a) milk did not inhibit ricin at concentrations of 10 or 100 ng/ml; (b) autoclaving 10 and 100 ng/ml ricin in DMEM at 121 °C for 30 min completely abolished activity; and (c) milk did not affect the activity of another ribosome inactivating protein, Shiga toxin type 2 (Stx2), produced by pathogenic Escherichia coli O157:H7. Unlike ricin, which is internalized into the cells via a galactose-binding site, Stx2 is internalized through the cell surface receptor glycolipid globotriasylceramides Gb3 and Gb4. These observations suggest that ricin toxicity may possibly be reduced at room temperature by a widely consumed natural liquid food.     

Identification of a new bioregulator acting in ultralow doses in bulb onion (<Emphasis Type="Italic">Allium cepa</Emphasis> L.)

A bioregulator that has physicochemical and biological properties similar to a group of bioregulators isolated from various animal tissues has been found in the bulb onion (Allium cepa L.). It was determined that the biological action of the plant bioregulator is determined by a peptide with molecular weight of 4036 ± 2 Da whose 18-C-terminal amino acid sequence consisted of 18 residues. On models of seed germination of some vegetable cultures, the ability of the bioregulator isolated from supernatant of onion extract in ultralow doses (10⁻¹³ mg of protein/ml) to inhibit growth and development was demonstrated.     

Surface display of acid protease on the cells of Yarrowia lipolytica for milk clotting

The acid protease structural gene was amplified from the genomic DNA of Saccharomycopsis fibuligera A11. When the gene was cloned into the multiple cloning site of the surface display vector pINA1317-YlCWP110 and expressed in the cells of Yarrowia lipolytica, the cells displaying the acid protease could form clear zone on the plate-containing milk indicating that they had extracellular acid protease activity. The cells displaying the acid protease can be used to effectively clot skimmed milk. The highest clotting milk activity (1,142.9 U/ml) was observed under the conditions of pH 3.0, 40 °C, 20 mM of CaCl₂, and 10% skimmed milk powder. We found that the acid protease displayed on the cells of Y. lipolytica which has generally regarded as safe status could be easily isolated and concentrated compared to the free acid protease. Therefore, the displayed acid protease may have many potential applications in food and cheese industries. This is the first report that the yeast cells displaying the acid protease were used to clot milk.     

Studies on the structure of the bioregulator purified from the rat brain

From the brain tissue of Wistar rats, we purified a bioregulator, which is active at ultralow doses. Using reversed-phase HPLC, we prepared a homogenous polypeptide with a molecular weight of 4749 ± 2 Da, which is responsible for the biological activity of the bioregulator. Using the CD spectroscopy method, we calculated the percentage of canonical elements of the secondary polypeptide structure in a solution. Using the methods of proteomics, we revealed that the structure of the investigated polypeptide was similar to the N-terminal sequence of a fragment of guanine-nucleotide binding G₀-protein subunit α-1.     

The dominant expression of functional human lactoferrin in transgenic cloned goats using a hybrid lactoferrin expression construct

Human Lactoferrin (hLF) is an iron-binding protein with multiple physiological functions. As the availability of natural hLF is limited, alternative means of producing this biopharmaceutical protein have been extensively studied. Here we report on the dominant expression of recombinant human lactoferrin (rhLF) in transgenic cloned goats using a novel optimised construct made by fusing a 3.3kb hLF minigene to the regulatory elements of the β-casein gene. The transgenic goat produced more than 30mg/ml rhLF in its milk, and rhLF expression was stable during the entire lactation cycle. The rhLF purification efficiency from whole goat milk is approximately 70%, and its purity is above 98%. Compared with natural hLF, the rhLF from transgenic goats has similar biological characteristics including molecular mass, N-terminal sequence, isoelectric point, immunoreactivity and digestive stability. More importantly, the purified rhLF showed specific anti-tumour activity in the mouse model of melanoma experimental metastasis. Therefore, our study shows that the large-scale production of functional rhLF in transgenic goat milk could be an economical and promising source of human therapeutic use in the future.     

In Vitro Effects of Different Resveratrol Concentrations on the Structural State of Mitochondrial Membranes Isolated from Pea Leaves

In this study, the effects of different concentrations of antioxidant resveratrol on microviscosity of mitochondrial membranes isolated from pea leaves were investigated. It was shown that resveratrol in physiological (5 × 10^–6 M) and ultralow (5 × 10^–14 M) doses changed the microviscosity and altered the structure of the membrane lipid bilayer. This antioxidant is thought to affect the activity of membrane proteins due to altered structures of lipid molecules that surround them and, in turn, influence mitochondrial activity and function. No change was found in the range between physiological and ultralow doses, which is a “dead” zone. Moreover, resveratrol in physiological concentrations was found to shift thermally induced structural transition to the lower temperature region; therefore, it can interfere with the normal regulation of natural processes

     

Antitumor effect of joint action of low intensity electromagnetic fields and ultra low doses of doxorubicin

Combined action of a low intensive physical factor and a chemotherapeutic agent in ultralow doses against Lewis lung carcinoma was studied. Antitumor activity of low intensiwe electromagnetic field was expressed as inhibition of tumor growth at 60% compare to control. Ultra low doses of doxorubicin as well as its standard dose resulted in inhibition of tumor growth by 60-70% in comparison with control. Joint action of both factors leaded to increasing in the antitumor effect that reached such level of tumor growth inhibition as 85% relative to control.     

Conserved phosphorylation of serines in the Ser-X-Glu/Ser(P) sequences of the vitamin K-dependent matrix Gla protein from shark, lamb, rat, cow, and human.

The present studies demonstrate that matrix Gla protein (MGP), a 10-kDa vitamin K-dependent protein, is phosphorylated at 3 serine residues near its N-terminus. Phosphoserine was identified at residues 3, 6, and 9 of bovine, human, rat, and lamb MGP by N-terminal protein sequencing. All 3 modified serines are in tandemly repeated Ser-X-Glu sequences. Two of the serines phosphorylated in shark MGP, residues 2 and 5, also have glutamate residues in the n + 2 position in tandemly repeated Ser-X-Glu sequences, whereas the third, shark residue 3, would acquire an acidic phosphoserine in the n + 2 position upon phosphorylation of serine 5. The recognition motif found for MGP phosphorylation, Ser-X-Glu/Ser(P), has been seen previously in milk caseins, salivary proteins, and a number of regulatory peptides. A review of the literature has revealed an intriguing dichotomy in the extent of serine phosphorylation among secreted proteins that are phosphorylated at Ser-X-Glu/Ser(P) sequences. Those phosphoproteins secreted into milk or saliva are fully phosphorylated at each target serine, whereas phosphoproteins secreted into the extracellular environment of cells are partially phosphorylated at target serine residues, as we show here for MGP and others have shown for regulatory peptides and the insulin-like growth factor binding protein 1. We propose that the extent of serine phosphorylation regulates the activity of proteins secreted into the extracellular environment of cells, and that partial phosphorylation can therefore be explained by the need to ensure that the phosphoprotein be poised to gain or lose activity with regulated changes in phosphorylation status.(ABSTRACT TRUNCATED AT 250 WORDS)     

The role of regulatory networks of the cell response to damages in radiation effects

In view of modern knowledge and concepts about components, function and mechanisms of response of cell molecular structures to damaging effects, response which is generating specialized modules of reactions, it is shown that main components of the mechanism of maintenance of genome constancy at ionizing radiation exposure are checkpoints of cell cycle, DNA repair and apoptosis. They operate under the control of a genetic system at participation of Tp53 gene, corresponding protein and of regulatory networks formed by cascades of mitogen-activated protein kinases (MAPK). At ionizing radiation exposure the MAPK special modules participate in formation of radiation effect: ERK 1/2 (extracellular signal-regulated kinase 1 and 2), JNK/SAPK (c-Jun N-terminal kinase/stress activated protein kinase) and p38 MAPK. Executing physiological functions of maintenance of normal life activity of cells, they do not lose this capacity after exposure to ionizing radiation, participating in formation of radiation effect in a wide range of doses, and are inactivated only by exposure to very high doses. It is concluded that in light of the modern data the main problem is not a problem of mechanisms of biological effect of ionizing radiation but a problem of biological mechanisms of radiation exposure.     

B cell activating properties of parotid protein.

A new biological activity of bovine parotid protein acting on immuno-competent lymphocytes to lead to polyclonal antibody responses was demonstrated. A significant amount of antibody to SRBC or antihapten antibody to TNP-SRBC, BPO-SRBC, or SA-SRBC was produced in mice by adding the appropriate doses of bovine parotid protein, suggesting that this protein may be a nonspecific B cell activator which acts on the B cells in a similar way as casein or gelatin.     

Composition of the milks of the bottlenose dolphin (Tursiops trucatus) and the Florida manatee (Trichechus manatus latirostris)

Milk samples from four individual bottlenose (Tursiops truncatus) and two Florida manatees (Trichechus manatus latirostris) of known lactation stages were analyzed for protein, carbohydrate and lipid composition, as well as for activity levels of alpha-lactalbumin, the regulatory protein of lactose synthase. The milk from both species had relatively high protein and lipid levels, as reported previously for other marine mammals. The major proportion of the lipid was in the form of triglycerides. Dolphin milk contained an average of 2.2% neutral sugars, which was essentially all in the form of lactose, as determined by several criteria. Manatee milk samples contained 0.6% of neutral sugars, and a larger proportion (about 2%) of amino sugars. Lactose was not detected by enzymatic assay or paper chromatography, but HPLC analysis indicated the presence of low levels of lactose together with two components that were tentatively identified as oligosaccharides. alpha-Lactalbumin activity, determined by assay with bovine galactosyltransferase, was found in both dolphin and manatee milk. The level in dolphin milk was comparable with that found in bovine and other milk, but the level in the manatee was less than 10% of that in the dolphin.     

Cognitive disorders in mice: cytokine signaling pathways as therapeutic targets

Surplus accumulation of regulatory T cells (Tregs) is known to be at the bottom of many morbid conditions, among them being neuropsychiatric diseases. In particular, Tregs may inhibit Th1 cells, including brain autoimmune lymphocytes, controlling the local microglial response and brain tissue homeostasis. The present study was undertaken in an attempt to suggest a novel approach for the treatment of maladaptation to mental stress associated with excessive Treg accumulation. Recently it was shown that alkylating drugs (ADs), such as melphalan and cyclophosphamide (Cy) in the dose 100-fold lower than cytostatic one are capable to disturb signal transduction by IL-2R. In this study we demonstrated that IL-2R is not a unique receptor, which may be blocked with ADs. Similar effect has been shown for two other surface receptors: TNFR and Fas. Molecular mechanisms of the receptor blockage were investigated on the model of TNF signaling. Study of NF-κB activity in nuclear extracts showed that alkylating agents act at the level of surface receptor or of the receptor platform. It was also shown that ADs administration in ultralow doses results in selective elimination of Tregs. In this study we used a new laboratory model of Treg accumulation in mice. Such Treg accumulation was associated with cognitive and behavioral abnormalities, which may be prevented by Cy administration.     

Synthesis and biologic activity of 3 beta-thiovitamin D3

We synthesized 3 beta-thiovitamin D3 from 7-dehydrocholesterol and tested its biological activity and protein binding properties. The thiovitamin was found to be a weak vitamin D agonist at high doses in vivo. It was poorly bound by both vitamin D-binding protein as well as by the intestinal cytosol receptor for 1,25-dihydroxyvitamin D. It did not increase the synthesis of calcium binding protein in the chick embryonic duodenum and did not block the activity of 1,25-dihydroxyvitamin D3 in this system. We conclude that 3 beta-thiovitamin D3 is a weak vitamin D agonist in vivo with no agonist activity or antagonist activity to 1,25-dihydroxyvitamin D3 in the chick embryonic duodenum.     

Distinct expression patterns of the subunits of the CCR4-NOT deadenylase complex during neural development

The stability of mRNA influences the dynamics of gene expression. The mammalian CCR4–NOT complex is associated with deadenylase activity, which shortens the mRNA poly(A) tail and thereby contributes to destabilization of mRNAs. The complex consists of at least nine subunits and predominantly forms a 2.0 MDa protein complex in HeLa cells. Accumulating evidence suggests that the CCR4–NOT complex is involved in cell growth and survival; however, the regulatory mechanisms of its biological activity remain obscure. Here, we analyzed the expression levels of the subunits of the CCR4–NOT complex in various mouse tissues and found that they showed distinct expression patterns. CNOT6, 6L, 7, and 10 were expressed nearly ubiquitously, whereas others were expressed in tissue-specific manners, such as those displaying especially high expression in the brain. Furthermore, CNOT2, 3, 6, and 8 were rapidly downregulated during differentiation of neural stem cells. These findings suggest that subunit composition of the CCR4–NOT complex differs among tissues and is altered during neural development, thereby imparting an additional layer of specificity in the control of gene expression.     

Detection of a single nucleotide polymorphism in the human alpha-lactalbumin gene: implications for human milk proteins

Variability in the protein composition of breast milk has been observed in many women and is believed to be due to natural variation of the human population. Single nucleotide polymorphisms (SNPs) are present throughout the entire human genome, but the impact of this variation on human milk composition and biological activity and infant nutrition and health is unclear. The goals of this study were to characterize a variant of human alpha-lactalbumin observed in milk from a Filipino population by determining the location of the polymorphism in the amino acid and genomic sequences of alpha-lactalbumin. Milk and blood samples were collected from 20 Filipino women, and milk samples were collected from an additional 450 women from nine different countries. alpha-Lactalbumin concentration was measured by high-performance liquid chromatography (HPLC), and milk samples containing the variant form of the protein were identified with both HPLC and mass spectrometry (MS). The molecular weight of the variant form was measured by MS, and the location of the polymorphism was narrowed down by protein reduction, alkylation and trypsin digestion. Genomic DNA was isolated from whole blood, and the polymorphism location and subject genotype were determined by amplifying the entire coding sequence of human alpha-lactalbumin by PCR, followed by DNA sequencing. A variant form of alpha-lactalbumin was observed in HPLC chromatograms, and the difference in molecular weight was determined by MS (wild type=14,070 Da, variant=14,056 Da). Protein reduction and digestion narrowed the polymorphism between the 33rd and 77th amino acid of the protein. The genetic polymorphism was identified as adenine to guanine, which translates to a substitution from isoleucine to valine at amino acid 46. The frequency of variation was higher in milk from China, Japan and Philippines, which suggests that this polymorphism is most prevalent in Asia. There are SNPs in the genome for human milk proteins and their implications for protein bioactivity and infant nutrition need to be considered.