Quality and safety evaluation of genetically engineered rice with soybean glycinin: analyses of the grain composition and digestibility of glycinin in transgenic rice.
The composition of nutritionally and physiologically important molecules in transgenic rice with the soybean glycinin gene was determined and compared with that of a non-transgenic control. Except for the levels of protein, amino acids and moisture, no marked differences were found between the two kinds of rice. The protein content of the transgenic rice was about 20% higher than the control (control, 6.5 g/100 g; transgenic, 8.0 g/100 g) with a concomitantly lower moisture content. This increased protein content mainly resulted from the increased glycinin expressed in the transgenic rice, and the protein was susceptible to gastric and intestinal digestion juices. In parallel with the increased protein content, some important amino acids lacking in quantity in normal rice were replenished. (+info)
Alignment of a sparse protein signature with protein sequences: application to fold prediction for three small globulins.
A novel algorithm has been developed for scoring the match between an imprecise sparse signature and all the protein sequences in a sequence database. The method was applied to a specific problem: signatures were derived from the probable folding nucleus and positions obtained from the determined interactions that occur during the folding of three small globular proteins and points of inter-element contact and sequence comparison of the actual three-dimensional structures of the same three proteins. In the case of two of these, lysozyme and myoglobin, the residues in the folding nucleus corresponded well to the key residues spotted by examination of the structures and in the remaining case, barnase, they did not. The diagnostic performance of the two types of signatures were compared for all three proteins. The significance of this for the application of an understanding of the protein folding mechanisms for structure prediction is discussed. The algorithm is generic and could be applied to other user-defined problems of sequence analysis. (+info)
Inhibition of initiation of protein synthesis by 7-methylguanosine-5'-monophosphate.
Translation of rabbit globin mRNA in a wheat germ protein-synthesizing system is inhibited by the nucleotide 7-methylguanosine-5'-monophosphate (m7G5'p) but not by other guanosine nucleotides without the 7-methyl group or with the phosphate in a different position. Translation of RNA of tobacco mosaic virus and poly(A) + HeLa RNA is also inhibited by m7G5'p. We show that m7G5'p prevents the association of mRNA with ribosomal subunits to form an initiation complex. We propose that m7G5'p interacts with a site on initiation factor(s) or ribosomes which is involved in mRNA recognition, presumably by binding to the 5'-terminal sequence m7G5'ppp. m7G5'p does not inhibit translation of poly(U) and RNA of satellite tobacco necrosis virus, which do not have the 5'-terminal sequence m7G5'ppp. In the case of RNA of satellite tobacco necrosis virus, some stimulation of its translation is consistently observed in the presence of m7G5'p; possible interpretations of this finding are discussed. (+info)
Safety assessment of transgenic potatoes with soybean glycinin by feeding studies in rats.
Feeding studies of transgenic potatoes with native and designed soybean glycinins in rats were done for four weeks. The designed glycinin has four additional methioninyl residues in the middle of the glycinin molecule. Rats were divided into four groups fed (I) only a commercial diet, (II) the diet plus non-transgenic potatoes, (III) the diet plus transgenic potatoes with native glycinin, and (IV) the diet plus transgenic potatoes with designed glycinin. Rats were fed 2,000 mg/kg-weight potatoes every day by oral administration. During the period tested, rats in each group (groups II, III, and IV) grew well without marked differences in appearance, food intake, body weight, or in cumulative body weight gain. No significant differences were also found in blood count, blood composition, and in internal organ weights among the rats after feeding potatoes (groups II, III, and IV) for four weeks. Necropsy at the end of experiment indicated neither pathologic symptoms in all rats tested nor histopathological abnormalities in liver and kidney. Judging from these results, the transgenic potatoes with glycinins are confirmed to have nearly the same nutritional and biochemical characteristics as non-transgenic one. (+info)
Total protein determination in urine: elimination of a differential response between the coomassie blue and pyrogallol red protein dye-binding assays.
BACKGROUND: The total protein content of urine is a good index of renal function, but its determination is unreliable. Protein dye-binding assays are simple, but they characteristically lack a uniform response to different proteins. METHODS: We investigated a differential response of the Sigma Microprotein Coomassie Brilliant Blue (CBB) and Pyrogallol Red-molybdate (PRM) protein dye-binding assays to urine, using human albumin, albumin/globulin, or urinary protein as calibrator. RESULTS: The urine protein values (n = 60) obtained with the CBB assay were 110-13 500 mg/L (mean, 2390 mg/L) compared with 160-18 300 mg/L (mean, 3470 mg/L) obtained with the PRM assay (CBB:PRM protein concentration ratio, 0.46-0.88, mean, 0. 69 +/- 0.10). The differential response was highly reproducible as indicated by Sigma urine control Level 1 (within-day CBB:PRM ratio, 0.68 +/- 0.02; between-day CBB:PRM ratio, 0.67 +/- 0.04) and Sigma urine control Level 2 (within-day CBB:PRM ratio, 0.60 +/- 0.01; between-day CBB:PRM ratio, 0.59 +/- 0.02). The use of urinary protein as a calibrator (rather than human albumin) greatly improved the agreement between the assays when applied to urine (y(CBB) = 0. 972x(PRM) - 16 vs y(CBB) = 0.685x(PRM) + 17). In studies using urine controls, this calibrator also improved agreement between the CBB, PRM, trichloroacetic acid (TCA), and benzethonium chloride protein methods and, to a lesser extent, agreement with the TCA-Ponceau S method. CONCLUSION: The use of a urinary protein calibrator improves the agreement between different methods used to determine total protein in urine. (+info)
Comparison of globulin mobilization and cysteine proteinases in embryonic axes and cotyledons during germination and seedling growth of vetch (Vicia sativa L.).
Vicilin and legumin, the storage globulins of mature dry vetch (Vicia sativa L.) seeds, are found in protein bodies which are present not only in the cotyledons, but also in the radicle, axis and shoot (together, for reasons of simplicity, here called axis). When at 24 h after the start of imbibition (hai) the radicle breaks through the seed coat a major part of the globulins in the axis has already been degraded, whereas in the cotyledons globulin breakdown cannot yet be detected. Globulin mobilization starts with the degradation of vicilin. At 48 hai when globulin mobilization in the cotyledons just begins, the axis is already nearly depleted of globulins. Mobilization of storage globulin is probably brought about by a complex of different cysteine proteinases (CPRs). The papain-like CPR2 and CPR4, and the legumain-like VsPB2, together with their mRNAs, are already present in axes and cotyledons of dry seeds. This means that they must have been formed during seed maturation. Additional papain-like CPRs are formed later during germination and seedling growth. CPR4 and VsPB2 together with their corresponding mRNAs become undetectable as germination and seedling growth proceed. VsPB2 and VsPB2-mRNA are substituted by the homologous legumain-like proteinase B and its mRNA. The composition of stored and newly formed CPRs undergoes developmental changes which differ between axes and cotyledons. It is concluded that storage globulin mobilization in germinating vetch seeds is started by stored CPRs, whereas the mobilization of the bulk of globulin is predominantly mediated by CPRs which are formed de novo. (+info)
Endogenous ouabain and its binding globulin: effects of physical exercise and study on the globulin's tissue distribution.
Ouabain, that has been isolated from bovine adrenals and hypothalamus, is a new cardiotonic steroid hormone, which is either synthesized in the adrenals or stored there after it has absorbed from the diet. Little is known in vivo which events may lead to the release of ouabain into blood. Moreover, a binding protein for cardiotonic steroids exists in blood, which binds cardiac glycosides with high affinity. It may affect the action of endogenous ouabain on heart and circulation, but the physiological function of this protein is unclear. To realize, which physiological stimuli in vivo may affect blood concentrations of endogenous ouabain and which function the cardiotonic binding protein may have in modulating ouabain effects, the effect of physical exercise on endogenous ouabain was studied and the tissue distribution of its binding protein was investigated. We found that endogenous ouabain changes rapidly in blood upon physical exercise and behaves like expected for a hormone of circulation. The cardiotonic steroid binding globulin shows the highest concentration in the kidney, which suggests that sodium pumps of the kidney are protected against its inhibition by ouabain which would lead not only to natriuresis but also to a deleterious loss of glucose, amino acids and phosphate. (+info)
Safety assessment of rice genetically modified with soybean glycinin by feeding studies on rats.
Feeding studies on rice genetically modified with soybean glycinin were performed on rats for four weeks. The rats were divided into three groups, each being fed on (I) only a commercial diet, (II) this diet plus control rice and (III) this diet plus rice genetically modified with glycinin. The rats were fed with 10 g/kg-weight of rice every day by oral administration. During the test period, the rats in every group grew well without marked differences in appearance, food intake, body weight, or cumulative body weight gain. There were also no significant differences in the blood count, blood composition or internal organ weights among the rats. Necropsy at the end of the experiment indicated neither pathological symptoms nor histopathological abnormalities in the liver and kidney. Judging from these results, the rice genetically modified with glycinin is considered to have been essentially the same in nutritional and biochemical characteristics as the control rice. (+info)