Order Of Decreasing Mobility Research Articles

CHEMICAL FORMS OF Zn, Mn, Fe and Pb IN SOIL SAMPLES FROM THE VICINITY OF SOME MAJOR DUMPSITES IN GOMBE METROPOLIS, GOMBE STATE NIGERIA

This research work is aimed at determining the chemical speciation of metals Zn, Mn, Fe and Pb in soil samples from three major dumpsites within Gombe metropolis, Gombe state. The renowned five steps Tessier sequential extraction method was employed in the extraction of the heavy metals. The metals were extracted into five fractions namely: Exchangeable (F1), carbonate bound (F2), Fe-Mn oxide bound (F3), Bound to organic matter (F4) and the residual fraction (F5) in order of decreasing mobility. The elemental analysis of the fractions was carried out using atomic absorption spectrometric technique. The results showed Zn was predominantly bounded to the exchangeable fraction with 32.66±0.31 mg/kg (54.18%) and least in the Fe – Mn oxide fraction with 0.01±0.00 mg/kg (0.02%). The trend in its abundance is in the order F1> F2>F5>F4>F3. Mn was predominantly associated with the bound to carbonates fraction with the value of 103.3.±3.30 mg/kg (56.14%) and least in the exchangeable with the value of 1.30±1.85mg/kg (2.13%) its occurred in the order F2>F3>F4>F5>F1. The concentration of Fe was highest in the residual fraction with the value of 25.90±1.75mg/kg (45.45%)and least in the carbonate bound fraction wi th 5.10±0.40 mg/kg (2.13%) the order is F5>F4>F3>F2>F1. Pb was not detected in most of the fraction but highest in bond to carbonate and bond to organic matter fraction with the values of 6.64±4.12 mg/Kg (70.64 %) and 2.76±0.10 mg/Kg (29.36 %) respectively in two different samples. It was however established that Zn, Mn and Pb were mostly associated with the first three fractions thus, showed high bio-availabilty whereas Fe was found in the residual fraction and is expected to be low in mobility and less bioavailable.

Interfacial interactions and complex segmental dynamics in systems based on silica-polydimethylsiloxane core–shell nanoparticles: Dielectric and thermal study

Effects of two types of silica particles, with different characteristics of porosity, on segmental mobility of poly(dimethylsiloxane), PDMS, in core–shell nanocomposites with two contents of polymer, 40 and 80 wt%, were studied by employing thermal (DSC) and dielectric (DRS, TSDC) techniques, under different annealing procedures. Filler morphology and polymer–particle interactions were found to affect PDMS crystallinity and segmental mobility. The dielectric techniques allowed the detection of four contributions to the segmental dynamics associated with the glass transition arising, in the order of decreasing mobility, from confined polymer chains in the pores of silica gel (αp relaxation), from the bulk (unaffected) amorphous polymer fraction (α relaxation), from polymer chains restricted between condensed crystal regions (αc) and from semibound polymer in an interfacial layer close to the nanoparticle surface (α′). For the core–shell nanocomposites with high PDMS content (80 wt%) the interfacial α′ relaxation process is found to have similar characteristics with that in conventional PDMS/silica nanocomposites, for lower PDMS content (40 wt%), however, the interfacial relaxation process exhibits distinct differences. The experimental findings are discussed in terms of models proposed for the description of conformations of polymers adsorbed onto a solid surface.

Dielectric and thermal studies of segmental dynamics in silica/PDMS and silica/titania/PDMS nanocomposites

ABSTRACTEffects of silica and silica/titania nanoparticles on glass transition and segmental dynamics of poly(dimethylsiloxane) (PDMS) were studied for composites of a core–shell type using differential scanning calorimetry, thermally stimulated depolarization current, and dielectric relaxation spectroscopy techniques. Strong interactions between the filler and the polymer suppress crystallinity (Tc, Xc) and affect significantly the evolution of the glass transition in the nanocomposites. The segmental relaxation associated with the glass transition consists of three contributions, arising, in the order of decreasing mobility, from the bulk (unaffected) amorphous polymer fraction (α relaxation), from polymer chains restricted between condensed crystal regions (αc relaxation), and from the semi‐bound polymers in an interfacial layer with strongly reduced mobility due to interactions with surface hydroxyls of silica and silica/titania nanoparticles (α′ relaxation). The evolution of surface affected CH3 groups, as well as the degree of interaction of PDMS molecules with surface hydroxyl groups as a function of treatment temperature, was assessed by Fourier transform infrared spectroscopy, thermogravimetry and differential thermal analysis. The effectiveness of silica/PDMS and silica/titania/PDMS nanocomposites as hydrophobic coatings was investigated by static contact angle measurements. It was shown that the presence of titania nanoparticles and adsorbed PDMS promotes the hydrophobic properties of the PDMS coating after treatment in the 80–650°C range. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41154.

Dielectric studies of segmental dynamics in poly(dimethylsiloxane)/titania nanocomposites

Differential scanning calorimetry, thermally stimulated depolarization currents and dielectric relaxation spectroscopy techniques, covering together a broad frequency range of 10 −4 to 10 6 Hz, were employed to investigate the effects of in situ synthesized titania nanoparticles on thermal transitions, segmental dynamics and interfacial interactions in poly(dimethylsiloxane)/titania nanocomposites. Titania particles (TiO 2, 20–40 nm in diameter) were prepared and well dispersed into the polymer network through sol–gel technique, aiming at stable and mechanically reinforced systems. The interactions between polymer and fillers were found to be strong, supressing crystallinity and affecting the temperature development of the glass transition. The segmental relaxation associated with the glass transition consists of three contributions, arising, in the order of decreasing mobility, from the bulk (unaffected) amorphous polymer fraction ( α relaxation), from polymer chains restricted between condensed crystal regions ( α c relaxation), and from the semi-bound polymer in an interfacial layer with strongly reduced mobility due to interactions with hydroxyls on the nanoparticle surface ( α΄ relaxation). The thickness of the interfacial layer was estimated to be in the range of 3–5 nm. Measurements using different thermal protocols proved very effective in analyzing the origin of each relaxation and the respective effects of filler addition.

Assessment of serum protein fractions in rainbow trout using automated electrophoresis and densitometry

Although rainbow trout (Oncorhynchus mykiss, Walbaum) are one of the most-studied fish, electrophoretic techniques and classification of serum protein fractions have not been standardized, such that clinically useful values are lacking. The aim of the present study was to evaluate preliminarily the serum protein fractions of rainbow trout using automated cellulose acetate electrophoresis and densitometry. Serum samples from 25 rainbow trout (Oncorhynchus mykiss, Walbaum) were electrophoresed on cellulose acetate plates and quantified using densitometry. A maximum of 6 fractions were identified and numbered, in order of decreasing mobility, as I, II, III, IV, V, and VI. In 3 of 25 (12%) samples, 6 fractions were identified; in 18 (72%) samples, 5 fractions were identified; and in 4 (16%) samples, 4 fractions were identified. Fractions I, V, and VI were always clearly identifiable, whereas fractions II and IV were frequently fused and indistinguishable from fraction III. The pattern with 5 fractions was the most probable type (chi(2), P<.01). The mean (+/-SEM) protein concentrations of the 6 fractions were I, 0.8+/-0.1 g/dL; II, 0.3+/-0.0 g/dL; III, 1.6+/-0.1 g/dL; IV, 0.3+/-0.1 g/dL; V, 0.6+/-0.0 g/dL; and VI, 0.2+/-0.0 g/dL. Based on comparison of serum and plasma electrophoretic patterns from 8 fish, fibrinogen was found in fraction V. Automated cellulose acetate electrophoresis and densitometry appear to be a practical method for estimation of serum protein fractions in rainbow trout.

Heterogeneity of α-cardiac myosin heavy chains in a small marsupial, Antechinus flavipes, and the effect of hypothyroidism on its ventricular myosins

The effect of drug-induced hypothyroidism on ventricular myosin gene expression was explored in a small marsupial, Antechinus flavipes. Pyrophosphate gel electrophoresis, SDS-PAGE and western blotting were used to analyse changes in native myosin isoforms and myosin heavy chains (MyHCs) in response to hypothyroidism. In some animals, five instead of the normal three native myosin components were found: V(1a), V(1b),V(1c), V(2) and V(3), in order of decreasing mobility. In western blots, V(1a), V(1b), and V(1c) reacted with anti-alpha-MyHC antibody, but not with anti-beta-MyHC, whereas V(2) and V(3) reacted with anti-beta-MyHC antibody. SDS-PAGE of the unusual ventricular myosins revealed three MyHC isoforms, two of which bound anti-alpha-MyHC antibody while the third bound anti-beta-MyHC antibody. We conclude that V(1a), V(1b), V(1c) are triplets arising from the dimerization of two distinct alpha-MyHC isoforms. Hypothyroidism, verified by metabolic studies, decreased alpha-MyHC content significantly (t-test, P < 0.001) from 91.6 +/- 5.9% (SEM, n = 4) in control animals to 67.2 +/- 5.7% (SEM, n = 4) in hypothyroid animals, with a concomitant increase in beta-MyHC content. We conclude that in adult marsupials, ventricular myosins are also responsive to changes in the thyroid state as found in eutherians, and suggest that evolution of the molecular mechanisms underlying this thyroid responsiveness predate the divergence of marsupials and eutherians.

Electrophoretic separation and characterization of urinary glycosaminoglycans and their roles in urolithiasis

Urinary polyanions recovered from the urine samples of kidney stone-formers and normal controls were subjected to preparative agarose gel electrophoresis, which yielded fractions 1–5 in a decreasing order of mobility. In both groups, chondroitin sulfates were identified in the fast-moving fractions and heparan sulfates in the slow-moving fractions. Furthermore, two types of heparan sulfates were identified based on their electrophoretic mobility: slow-moving and fast-moving. The fractionated urinary polyanions were then tested in an in vitro calcium oxalate crystallization assay and compared at the same uronic acid concentration, whereby, the chondroitin sulfates of stone-formers and heparan sulfates of normals enhanced crystal nucleation. Fraction 5 of the normals, containing glycoproteins (14–97 kDa) and associated glycosaminoglycans, were found to effectively inhibit crystallization. Papainization of this fraction in stone-formers revealed crystal-suppressive effects of glycoproteins, which was not seen in similar fractions of normals. It was concluded that glycoproteins could modulate the crystal-enhancing glycosaminoglycans such as chondroitin sulfates of stone-formers but not in normals. The differing crystallization activities of electrophoretic fraction 1 of normals and stone-formers revealed the presence of another class of glycosaminoglycan–hyaluronan. Hence, in the natural milieu, different macromolecules combine to have an overall outcome in the crystallization of calcium oxalate.

Litter production, decomposition and nutrient return of uplifted coral reef tropical forest

Four habitat types in a 10-ha permanent plot of an uplifted coral reef forest in southern Taiwan were chosen and subjected to systematic litterfall related processes. Ebenaceae and Euphorbiaceae were the dominant families. The common species in the four habitats were Diospyros maritime, Ficus benjamina and Melanolepis multiglandulosa. Habitat I on the flat terrace was dominated by Bischofia javanica and Palaquium formosanum; habitat II on the ridge of exposed coral reef was dominated by Aglaia formosana and Pouteria obovata; habitat III on the sedimentary basin was dominated by Macaranga tanariu; habitat IV at the bottom of valley was dominated by Pisonia umbellifera. Litter productions, decomposition processes and nutrient returns were monitored over a 12-month period in the four habitats. Bulk litter was gathered from traps for monthly accession of litterfall. Mixed-species litter bags containing equal portions of the individual species were used to measure the decomposition constants of the leaf litter. Fresh and decomposing litters were analyzed for C, N, P, Ca, Mg, K and Na. Experimental results indicated that mean monthly litterfall in all the habitats displayed a marked seasonal pattern, with spring troughs and summer, autumn and winter peaks associated with the typhoon and monsoon seasons. The annual litterfall ranged from 6.98 to 9.13 Mg ha −1 year −1, is within but in the higher range for tropical forests. The litterfall production in habitats I and IV was significantly ( p < 0.05) exceeding that in habitats II and III. This phenomenon probably occurs because the dominant tree species of habitat II are relatively adapted to strong wind, and the leaves survived for a long time on the exposed coral reef; meanwhile, habitat III comprised secondary forest which was dominated by early succession tree species with lower leaf area index and basal area than those in other habitats. Significant differences in initial C concentration in the leaf litter were observed in the four habitats. Carbon release from the leaf litter was fastest in habitat IV, while the thin and less rigid leaves without prominent skeletal tissues of Pisonia umbellifera are easily decomposed. The mass and nutrients in the leaf litter could be arranged sequentially in order of decreasing mobility: Ca > Mg = N > Na > K > P > mass > C. Carbon was returned to the forest floor in the highest amount, and the next element was Ca which ranged from 196 to 324 kg ha −1 year −1. Surprisingly, the annual returns of Ca significantly exceeded those of N, and differed significantly from those of other tropical forests.

Electrophoretic and immunochemical evidence showing that marsupial limb muscles express the same fast and slow myosin heavy chains as eutherians.

Limb muscles of eutherian (placental) mammals express a slow and three fast isoforms of myosin heavy chain (MyHC), but little is known about marsupial MyHCs. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of limb MyHCs from seven marsupial species, spanning two orders, revealed four components, each of which specifically cross-reacted in Western blots with a monoclonal antibody (mAb) against a corresponding eutherian MyHC. For all seven species, the relative mobility of the band identified by each mAb matched that in the rat, suggesting that the four are homologous to eutherian slow, 2B, 2X and 2A MyHCs, respectively, in the order of decreasing mobility. Immunohistochemical analysis of fast marsupial limb muscles identitied four different fiber populations whose relative fiber size spectra (IIA<slow=IIX<IIB) are consistent with corresponding eutherian fiber types. These results show that the four MyHC genes were shared by the common therian ancestor, and suggest that other eutherian fiber type specific properties may apply to marsupial muscles.

Mnium orientale sp. nov. from Japan Is Morphologically and Genetically Distinct from M. hornum in Europe and North America

Mnium orientale sp. nov. from Japan Is Morphologically and Genetically Distinct from M. hornum in Europe and North America

Cross-linking of porin with glutardialdehyde: a test for the adequacy of premises of cross-linking theory

Exposure of porin from Escherichia coli to glutardialdehyde followed by SDS-gel electrophoresis in 3% polyacrylamide yielded three bands that were identified in order of decreasing mobility as monomers and two and three cross-linked polypeptide chains. The distribution of protein among the three species for different extents of reaction showed a remarkably good agreement with corresponding values predicted from cross linking theory for an oligomer composed of three identical subunits arranged according to a 3-fold rotation axis. Electrophoresis performed in 7.5% polyacrylamide yielded four bands that were assigned to polypeptide chain monomers, dimers, and two types of trimers carrying two and three intersubunit cross-links. Our findings provide evidence that the central premise of cross-linking theory, viz. that the intersubunit cross-links formed upon exposure of a protein to a bifunctional reagent be governed by the symmetry of the molecule, is valid. Careful interpretation of cross-linking experiments thus proves an effective method to assess the oligomeric structure of a protein and reveal the symmetry underlying the spatial arrangement of the subunits within the molecule.

Expression of α-glycerophosphate dehydrogenase during the development and aging of malaria vector Anopheles stephensi (Diptera: Culicidae)

α-Glycerophosphate dehydrogenase (GPDH) expression during the complete development and aging of Anopheles stephensi has been studied by electrophoretic and spectrophotometric techniques. Single gene locus seems to govern the developmental expression of three isozymes numbered from GPDH-1 to GPDH-3 in order of decreasing mobility. GPDH-3 was present in all the stages of development. GPDH-1 disappeared during senescence. GPDH-2, the band of intermediate mobility, was adult specific. GPDH-1 has been indicated to be more suitable for energy metabolism and GPDH-3 for lipid biosynthesis. Three codominant alleles control the four electrophoretic variants revealed in the laboratory strain. Quantitatively, the activity of GPDH continuously increased during development and showed its peak on day-4 adults of both sexes. However, the activity decreased during senescence. Tissue and sex specific differences in isozymes pattern have also been analysed. Changes in isozymes and specific activity have been correlated with the various physiological and morphological events occurring during development.

Molecular symmetry and arrangement of subunits in extracellular hemoglobin from the nematode Ascaris suum

The arrangement of subunits and molecular symmetry of extracellular hemoglobin from the nematode Ascaris suum, an 11.7S molecular of molecular mass 332 kDa and composed of eight identical subunits, was studied. Dissociation of the molecule at alkaline and acid pH yielded 4.6S and 2.7S components, identified as polypeptide-chain dimers and monomers, respectively. Cross-linking with glutardialdehyde followed by SDS/PAGE resulted in a maximum number of eight bands identified in order of decreasing mobility as monomeric and 2-8 cross-linked-polypeptide-chain species. Comparison with values predicted from theory shows that the distribution of protein among the various cross-linked species, obtained after different extents of exposure to cross-linker, is consistent with a two-layered arrangement of subunits involving one type of interaction between subunits from different layers and another between subunits within the same layer. Electron micrographs of the molecule showed two profiles, a square and a rectangle. We propose a model for the molecule which is eight subunits arranged in two layers, stacked in an eclipsed orientation. The proposed model is consistent with the results from sedimentation, cross-linking and electron microscopy. Taken together, our findings indicate D4 symmetry for Ascaris hemoglobin.

High-performance capillary electrophoresis of histones

A high-performance capillary electrophoresis (HPCE) system was developed for the fractionation of histones. This system involves electroinjection of the sample and electrophoresis in 0.1 M phosphate buffer (pH 2.5) in a 35 cm × 50 μm I.D. coated capllary. Electrophoresis was accomplished in 9 min, separating a whole histone preparation into its components in the following order of decreasing mobility: (MHP) H3, H1 (major variant), H1 (minor variant), (LHP) H3, (MHP) H2A (major variant), (LHP) H2A, H4, H2B and (MHP) H2A (minor variant), where MHP is the more hydrophobic component and LHP is the less hydrophobic component. This order of separation is very different from that found in acid-urea polyacrylamide gel electrophoresis and in reversed-phase high-performance liquid chromatography and, thus, brings the histone biochemist a new dimension for the qualitative analysis of histone samples.

&lt;i&gt;Datura stramonium&lt;/i&gt; Agglutinin-Reactive &amp;alpha;-Fetoprotein Isoforms in Hepatocellular Carcinoma and Other Tumors

By means of Datura stramonium agglutinin (DSA) affinity electrophoresis, human alpha-fetoprotein (AFP) was resolved into five bands, AFP-D1, D2, D3, D4 and D5, in order of decreasing mobility. AFP-D1, which had no affinity for DSA, comprised more than 84% of the intensity of total AFP bands. The percentage of AFP-D2 increased marginally in hepatitis and liver cirrhosis with or without hepatocellular carcinoma. AFP-D3 increased characteristically in hepatocellular carcinoma and AFP-D4, which had the highest affinity for DSA, increased up to 12% in other tumors, mostly of gastrointestinal origin. AFP-D5 showed no consistent changes among the benign and malignant diseases. The assay of AFP-D3 and D4 proved useful as a highly specific marker of hepatocellular carcinoma and other tumors, respectively.

Sexually dimorphic polypeptides in developing antennal sensory neurons of an insect

Many insects have sexually dimorphic antennae with sensilla peculiar to one sex specialized to detect sex pheromones released by the other sex. In the moth Manduca sexta, the axons of receptor cells in the male-specific sensilla as well as those common to both sexes terminate in the antennal lobes of the brain. We have used 2-dimensional electrophoresis (2DE) to study some of the proteins that are produced by sensory receptor cells in developing antennae and transported through their axons to the brain. Extracts of antennal nerves from mature male and female M. sexta yield nearly identical 2DE patterns of proteins after staining or fluorography. Gels prepared from antennal nerves of developing animals, however, exhibit a sexual dimorphism in the quantitative pattern of at least 2 classes of proteins. One class consists of four 49 kDa proteins of similar charge, designated 49a, 49b, 49c, and 49d in order of decreasing mobility on nonequilibrium pH gradient electrophoresis gels. The total amount and apparent rate of synthesis of 49b and 49d are ca. 4- to 7-fold greater in antennal nerves of developing males than in those of females. Protein 49c is comparably enriched in female antennal nerves, while 49a is enriched ca. 1.2-fold in females. The second class consists of a single polypeptide of 24 kDa, which is nearly undetectable in silver-stained gels but was shown to be ca. 9-fold enriched in males by fluorography. At the end of adult development, male and female moths have similar patterns of the 49 kDa polypeptides, and synthesis of the 24 kDa polypeptide is reduced to nearly undetectable levels. The patterns of sexual dimorphism thus appear to be associated with the growth and maturation of antennal sensory axons into the antennal lobes. Biosynthesis of the 24 kDa polypeptide was nearly undetectable in antennal lobes or fragments of antennal nerves incubated in vitro with radiolabeled methionine. The 49 and 24 kDa polypeptides appear to belong to separate classes of rapidly transported proteins. The 24 kDa polypeptide is among the most rapidly transported proteins; it is found exclusively in a particulate fraction and is associated with plasma membrane but apparently not mitochondria. The 49 kDa polypeptides are found in both the particulate and soluble fractions; the more basic 49a and 49b are enriched in the particulate fraction, while the more acidic 49c and 49d are enriched in the soluble fraction.

A mutational analysis of spliceosome assembly: evidence for splice site collaboration during spliceosome formation.

We have analyzed the pathway of mammalian spliceosome assembly in vitro using a mobility retardation assay. The binding of splicing complexes to both wild-type and mutant beta-globin pre-RNAs was studied. Three kinetically related, ATP-dependent complexes, alpha, beta, and gamma, were resolved with a wild-type beta-globin substrate. These complexes formed, both temporally and in order of decreasing mobility, alpha----beta----gamma. All three complexes contained U2 snRNA. The RNA intermediates of splicing, i.e., free 5' exon and intron lariat + 3' exon, were found predominantly in the gamma complex. The RNA products of splicing, i.e., ligated exons and fully excised intron lariat, were found in separate, postsplicing complexes which appeared to form via breakdown of gamma. Mutations of the 5' splice site, which caused an accumulation of splicing intermediates, also resulted in accumulation of the gamma complex. Mutations of the 3' splice site, which severely inhibited splicing, reduced the efficiency and altered the pattern of complex formation. Surprisingly, the analysis of double mutants, with sequence alterations at both the 5' and 3' splice sites, revealed that the 5' splice site genotype was important for the efficient formation of a U2 snRNA-containing alpha complex at the 3' splice site. Thus, it appears that a collaborative interaction between the separate 5' and 3' splice sites promotes spliceosome assembly.

Influence of elevated ecosystems levels on litter decomposition and mineralization

Litter decomposition was studied at two forested watersheds in east Tennessee which differed primarily in their past history of atmospheric S input. Cross Creek Watershed, located near a large coal-fired power plant, has received greater S inputs than the more remote Camp Branch Watershed. Decomposition was estimated through the measurement of forest floor respiration, litter microflora populations, litter and soil microarthropod populations, and litter nutrient status. Average forest floor respiration rates were very similar, 6.78 g CO2 m−2 day−1 or 2472 g m−2 yr−1 at Camp Branch and 6.86 g CO2 m−2 day−1 or 2505 g M−2 yr−1 at Cross Creek. Fractional loss rates provided estimates of annual decay rates (k) of 0.35 and 0.39 for Camp Branch and Cross Creek, respectively. Litter decomposition was estimated to contribute 23% of the total CO2 output at Camp Branch and 26% at Cross Creek, while root respiration accounts for about 43 to 46%. Bacterial and fungal populations were about equal in size at both watersheds, with bacteria averaging 100 × 106 g−1 of litter and fungi 23 × 106 g−1 of litter. Total numbers of arthropods averaged 34% greater at Camp Branch. Acarina populations averaged 59% higher at Camp Branch, while Collembola numbers were about equal at the two watersheds. Nutrient mobility in the litter and soil was similar at both watersheds. The order of decreasing mobility was K, Mg, Ca, S, N, and P. Litterfall nutrient concentrations were slightly higher for all elements at Cross Creek, resulting in greater litter concentrations of Ca and Mg. Litter concentrations of S and N, however, were significantly greater at Camp Branch, indicating watershed differences in the loss rates and cycling processes of these elements. There were no differences between the loss rates or litter concentrations of P, K, and Na at either site. Overall, decomposition was similar at the two watersheds. Historic S inputs do not appear to have had a major effect on decomposition rate or decomposer organisms with the possible exception of lowered arthropod populations at Cross Creek.

The isomyosins of rabbit middle ear muscles.

Isomyosins of the two middle ear muscles of rabbit have been separated by electrophoresis in non-dissociating conditions. Tensor tympani has four isomyosins called MM1 to MM4 by order of decreasing mobility. Stapedius has two isomyosins, similar to MM1 and MM4. MM1 and MM2 have the same mobility than FM2 and FM3, fast isomyosins observed in psoas. MM4 has the same mobility than IM, a slow isomyosin observed in extensor digitorum longus. MM3 is absent in soleus, psoas or extensor digitorum longus. Slow myosin (SM) of soleus and fast myosin (FM1) of psoas are not observed in middle ear muscles.

“Whey” proteins of milk of the red ( Macropus rufus) and eastern grey ( Macropus giganteus) kangaroo

1. 1. A comparison is made of gel electrophoretic patterns of the “whey” proteins of the milk of red ( Macropus rufus) and eastern grey ( Macropus giganteus) kangaroos at various stages of lactation. Qualitative and quantitative changes occur with time during the mature phase of lactation of both types. Their onset is related solely to the stage of lactation. “Whey” proteins are isolated and characterised and the nature of protein changes determined for the first time. 2. 2. The anodic electrophoretic pattern is divided into 6 main zones (designated A–F in order of decreasing mobility) and 2 cathodic zones (G and H) that are only detected in the milk of M. giganteus. 3. 3. Zones A, B and C are milk specific. Zone B is present throughout lactation in both species and is an α-lactalbumin. Zones A and C are present only in late lactation, zone C, usually, but not always, appearing first. Zone A is an α-lactalbumin in M. giganteus, but is not an α-lactalbumin in M. rufus. Zone C appears to be the same protein in both species and is possibly a β-lactoglobulin. 4. 4. Zone D is kangaroo serum albumin and zone E is possibly a β 2-microglobulin, Zone F contains three main iron (III) binding bands whose relative intensity varies with stage of lactation. Their intensity differs from the corresponding blood serum transferrin bands. 5. 5. Zone H of Macropus giganteus is a lysozyme. 6. 6. Lactose is present in the milk, but is not the principal sugar. 7. 7. The significance of the results is discussed.