Genetic variability and improvement of seed proteins in wheat

Summary Albumins, globulins, gliadins and glutenins presumably comprising 100 percent of the wheat seed proteins were sequentially extracted and electrophoresed on SDS-polyacrylamide gels. The SDS-electrophoretic patterns within each of the four fractions from T. boeotiaum, T. urartu, T. turgidum, T. timopheevii, T. aestivum, Ae. speltoides and Ae. squawosa were similar. They differed from one species to another only in a few minor components or density of certain components. Similarity in MW's of components, as indicated by the SDS-electrophoretic patterns, suggests that the wheats and Aegilops exhibit no variability for structural genes coding seed proteins. A minimum of 60 to 70 and a maximum of 360 to 420 structural genes with major or minor effects control the total seed protein in T. aestivum. Presumably, only one or the other homoeoallele was expressed in the polyploids. Different components of albumins and globulins presumably had distinct MW's and amino acid composition, while the components of gliadins and glutenins could be classified into a few groups each containing one or more components with the same MW and nearly identical amino acid composition. The genes for components with similar MW's and amino acid composition arose through multiplication of a single original gene and perhaps share the same regulatory mechanism. Seed protein content and quality in wheat might be improved through the incorporation of structural genes, coding for polypeptides with distinct MW's, from distantly related species, rather than by manipulation of the structural genes within the Triticum-Aegilops group. Regulatory mutants similar to opaque-2 of corn could be used to alter the proportion of gliadins in relation to albumins and globulins, to improve amino acid composition of wheat proteins.     

Genetic studies in Paraguay: blood group, red cell, and serum genetic patterns of the Guayaki and Ayore Indians, Mennonite settlers, and seven other Indian tribes of the Paraguayan Chaco

Genetic studies of 540 Paraguayan Indians from nine tribal groups and 51 Mennonites are presented for ABO, MNSs, P₁, Rh, Kell, Lewis, Duffy, Diego; for serum immunoglobulins and haptoglobins, G6PD-deficiency, and thalassemia trait. Group O gene frequencies for all Indian groups were 1.00; for r (cde), 0.00. Tapiete, Lengua, Toba, and Sanapana R_z (CDE) frequencies were among the highest ever reported. N frequencies were high for Ache Kwera (Guayaki), Lengua, Cheroti, Guarayu, Tapiete; N and s low for Ayore. MS frequencies were high for Sanapana, Lengua, Ayore; Ns for Tapiete. Diego was notably absent for Toba, Lengua, Guarayu, Tapiete, Ayore. Homogeneous frequencies for Fy^a (1.000) occurred among Guarayu and Tapiete, and for P₁ among Guayaki. Inv(a) frequencies were low for Cheroti, Chulupi, Guayaki. Hp 1 among Guayaki (Ache Kwera 0.15) is lowest ever reported. G6PD deficiency and abnormal hemoglobins were uniformly absent from all groups. Mennonite results were homogeneous and point toward Dutch origins. Differences among groups studied, and between Paraguayan and other Amerinds emphasize importance of genetic drift and founder principle. Abandonment of their tribes by mixed-blood offspring is partly responsible for apparent genetic purity and homogeneity of groups.     

Analysis of proteins in microsamples of rat airway surface fluid by capillary electrophoresis

A thin layer of airway surface fluid (ASF) lining the pulmonary airways plays an important role in the primary defense mechanisms of the lung against bacterial infection. However, little is known about the composition of ASF due to the thinness (typically 5–30 μm in healthy animals) of the fluid layer and its relative inaccessibility, which causes considerable difficulties in sample collection and subsequent analysis. We have used a novel technique of capillary sampling coupled with capillary electrophoresis (CE) to analyze the protein composition of rat ASF. CE analyses were performed under two different conditions: a borate buffer, pH 9.1, or a phosphate buffer, pH 2.5, with 0.5 mM spermine. The different selectivities afforded by the two methods aid in peak identification, and quantitation of most of the major species was possible using both separation conditions. Albumin, transferrin and globulins are observed to be the major protein components in rat ASF, at concentrations of 28 mg ml⁻¹, 4.0 mg ml⁻¹ and 34 mg ml⁻¹ respectively, in comparison to 31 mg ml⁻¹, 3.1 mg ml⁻¹ and 40 mg ml⁻¹, respectively, in rat plasma.     

Interaction of human fibrinogen with divalent metal chlorides

Precipitation of human fibrinogen in 0.15 m NaCl occurred at pH 7.4 (Tris-HCl buffer) when ZnCl₂, CuCl₂, NiCl₂, or CoCl₂ were added beyond their respective critical concentrations. The critical concentrations were about $\text{4 × 10}{}^{\mathrm{?5}}\text{m}\text{ZnCl}{}_2\text{, 6 × 10}{}^{\mathrm{?5}}\text{m}\text{CuCl}{}_2\text{, 3 × 10}{}^{\mathrm{?4}}\text{m}\text{NiCl}{}_2\text{and}\text{1 × 10}{}^{\mathrm{?3}}\text{m}\text{CoCl}{}_2$. At pH 5.8 2-(N-morpholino)-ethane sulphonic acid buffer, the critical concentrations were found only for CuCl₂ and ZnCl₂, and were about $\text{3 × 10}{}^{\mathrm{?5}}\text{and}\text{3 × 10}{}^{\mathrm{?4}}\text{m}$, respectively. CaCl₂ and MgCl₂ were not effective up to $\text{1 × 10}{}^{\mathrm{?2}}\text{and}\text{2 × 10}{}^{\mathrm{?2}}\text{m}$ at pH 7.4 and 5.8, respectively. At pH 7.4, precipitation was better in 0.015 m NaCl than in 0.15 m NaCl for both CuCl₂ and ZnCl₂. Little or no conformational change was indicated on binding Cu²⁺ ions. The fluorescence of tryptophan was quenched only by CuCl₂, while other metal ions (ZnCl₂, NiCl₂, CoCl₂ and CaCl₂) were ineffective as quenchers.     

Effects of serum,its protein and lipid extracts,and commercial serum proteins and lipid on the isolated frog heart

Summary This study investigates the inotropic effects of serum, its protein and lipid extracts, and commercial serum proteins and lipid on the isolated, spontaneously-beating heart and superfused, hypodynamic ventricle of the frog. Serum taken from either man, horse, calf, frog, or rabbit evoked marked positive inotropic responses which were unaffected by cholinergic, serotonergic, and adrenergic receptor antagonists. Dialysed serum (dialisand) and void volume fractions from Sephadex G200–120 columns corresponding to large molecular weight constituents evoked marked positive inotropic responses. When serum was separated into fractions containing either proteins or lipids/lipoproteins by high-density ultracentrifugation or activated charcoal, both extracts evoked marked positive inotropic responses. Commerical serum globulins and serum containing a high proportion of immunoglobulins elicited large increases in contractile force, whereas serum albumin evoked a negative inotropic effect. Serum which was either boiled and/or treated with chymotrypsin to denature proteins also caused a marked increase in isometric twitch tension in the frog heart. Similar inotropic response was obtained with fractions of boiled serum eluted on columns of Sephadex G200–120. These fractions corresponded to molecular weight in the region of 60–70 kDa. However, the inotropic effect of boiled serum was abolished following pretreatment with lipase. Superfusion of frog hearts with commercial cardiolipin resulted in marked dose-dependent increases in contractile force. The results demonstrate the presence of at least two large molecular weight cardioactive principles in serum. These substances are comparable in size to constituents of serum proteins (e.g., globulins and immuno-globulins) and serum lipids/lipoproteins (e.g., cardiolipin) and may serve as physiological regulators of cardiac function.Abbreviations Ca ²⁺ Calcium - Da dalton - IgG immunoglobulins - Na ⁺ Sodium - K ⁺ potassium     

Variation of plasma protein parameters in four free-ranging reindeer herds and in captive reindeer under defined feeding conditions

Plasma total protein (TP), albumin (ALB) and globulin (GLOB) concentrations and albumin/globulin ratio (A/G) were analysed from blood samples collected from free-ranging reindeer (Rangifer tarandus tarandus) herds at varying times of year. The same parameters were followed in nine captive reindeer with varying protein and energy intake. Variation in the blood constituents of free-ranging reindeer was analysed in relation to different extrinsic and intrinsic factors and compared to findings from captive animals, allowing the analysis of effects of protein and energy intake. There was large overall variation in TP, ALB, GLOB and A/G ratio in the free-ranging animals, ranging between 36-110 g/L, 18-59 g/L, 17-59 g/L and 0.5-2.1. The variation between months and years was significant for all variables except the A/G ratio, where no year effect was noted. Increase in live body mass was associated with a small significant increase and pregnancy with a small significant decrease in all dependent variables, except for the A/G ratio. Age did not have a significant effect on any of the blood constituents when body mass was included in the same model. In captive animals, feeding lichens with low protein content was related to a significant decline in TP, ALB and GLOB, but not in the A/G ratio, whereas feeding commercial ration increased plasma TP, ALB and GLOB significantly. Extrinsic factors such as season and year explained majority of variation in the blood constituents of free-ranging reindeer, whereas body mass, pregnancy and age had only a minor influence. It is concluded that plasma TP and ALB, and to a lesser extent GLOB and A/G ratio may serve as nutritional biomarkers of reindeer.     

Electrophoretic profiles and amino acid composition of rice endosperm proteins of a mutant with enhanced lysine and total protein after backcrosses for germplasm improvements

 Seed storage proteins from in vitro-derived rice mutants improved by several backcrosses to ‘Calrose 76’ and BC₂ and BC₃ were characterized for changes in five different solubility classes. Albumins, rsealb (water-soluble globulins), true salt-soluble globulins, prolamins and glutelins were SDS-PAGE separated in a single dimension, and some two-dimensionally, to identify protein modifications. The genetic transmission of the enhanced-lysine mutants in backcrosses and the linkage of lysine with grain chalkiness were confirmed. Advanced lines had altered globulin profiles similar to those of unimproved lines. Chalky/ enhanced-lysine phenotypes had similar prolamin and glutelin profiles in the mutant and controls at the same protein level. Mutants had increased levels of globulins at 50 kDa and 33 kDa but had substantially less protein at 25 kDa than the controls. High protein in the mutant contributed to an increase in prolamins and the major storage proteins in both the globulins and glutelins. A significant decrease in low-molecular-weight, 15- to 18-kDa albumins was associated with the chalky/enhanced-lysine mutant phenotype. Two proteins in the 15- to 18-kDa group were amino acid sequenced, and database comparisons identified these proteins as allergens. Advanced lines downregulated for allergens and with enhanced-lysine/protein but with normal fertility and seed weight should be useful in breeding programs for nutritional quality. Received: 14 October 1996 / Accepted: 8 November 1996     

Identification of embryonal antigens of maize: Globulins as primary reserve proteins of the embryo

Normal and -irradiated caryopses of Zea mays L. were germinated, and the degradation of embryonal antigens (EA) was followed in the endosperms, scutella and embryonic axes of the seedlings, using double immunodiffusion, immunoelectrophoresis and quantitative immunoprecipitation. The predominant transient EA were presumed to be storage proteins related to the reserve globulins of dicotyledonous seeds. Therefore globulins were isolated from maize scutella, purified by (NH₄)₂SO₄ fractionation and isoelectric precipitation, and the molecular weights of the polypeptide units were estimated by discontinuous sodium-dodecyl-sulphate slab electrophoresis. The globulins were found to be identical with the predominant EA and amounted to about 40% of the protein nitrogen in the embryos of mature, non-germinated caryopses. The presumed reserve function of the globulins and the characteristic time course of their degradation in embryonic axes and scutella of maize seedlings are discussed in relation to the two-step pattern of mobilization of nitrogen reserves in germinating cereal caryopses.Abbreviations AG, AR and AS antisera to globulins and to root and scutellum proteins, respectively - CA common antigens - DAP days after pollination - EA embryonal antigens - ME 2-mercaptoethanol - SDS-PAGE discontinuous sodium-dodecylsulphate slab polyacrylamide-gel electrophoresis - TCA trichloroacetic acid     

A family of endosperm globulins encoded by genes located in group 1 chromosomes of wheat and related species

Summary A new group of proteins soluble in salt solutions and organic solvents (70% ethanol and chloroform-methanol mixtures), but not in water, has been isolated from wheat and rye endosperm. The molecular weights (23–26 kDa) and amino acid compositions of the different fractions characterized suggest a high degree of homology among the major components of the fractions in wheat and rye. Compensating nulli-tetrasomic and ditelosomic lines of hexaploid wheat have been analysed by two-dimensional electrophoresis and genes for these proteins have been assigned to the short arms of chromosomes 1 A, 1 B and 1 D. A similar analysis of Triticum aestivum/Secale cereale and T. aestivum/Agropyron elongatum addition and substitution lines has shown that genes for the corresponding globulins are located in the short arms of group 1 chromosomes of these species.