Characterization of histones from plutei larvae of the sea urchin Tetrapygus niger

• 1.1. Histones were isolated from plutei larvae of the sea urchin Tetrapygus niger and analysed electrophoretically. Individual histones were purified and their amino acid compositions were determined.
• 2.2. The electrophoretic analysis revealed that larval histones are microheterogeneous; H1 exhibits four subforms, the nucleosomal core histones H2A, H2B and H3 were resolved into three subforms each and H4 had two subforms.
• 3.3. The comparisons of the amino acid compositions of plutei larvae histones with data from the literature of homonimus late variants isolated from gastrulas of other sea urchin species, indicate that late histone variants are conserved proteins with a very slight degree of species specificity and with general features of classical histones.

     

Aggregation of the histone h1 from the fruit fly Ceratitis capitata through disulphide bridges. Studies on their complexes with DNA

• 1.1. Three different major components, BG1, BG2 and BG3, have been obtained when the histone H1 from the fruit fly Ceratitis capitata is oxidized in vitro, separated by gel permeation chromatography and characterized by both amino acid analysis and polyacrylamide electrophoresis.
• 2.2. BG1 and BG2 correspond to the aggregation products by formation of intermolecular disulphide bridges, while BG3 is a monomeric component which shows the presence of one intramolecular disulphide bridge.
• 3.3. Structural studies by both circular dichroism and controlled tryptic digestion on BG1, BG2 and BG3 show the native conformation of H1 from the insect changes slightly and in a different range in each component.
• 4.4. All the subfractions induce PSI structure in DNA and stabilize the double helix of DNA, although quantitative differences appear.

     

Variability of histone H1 in rabbit populations

• 1.1. Perchloric acid-soluble proteins containing H1 histone as a main component were isolated from whole liver, lung and kidney of New Zealand White, Chinchilla, French Silver and Czech Spotted rabbits.
• 2.2. Proteins were resolved in a two-dimensional polyacrylamide slab gel into 4–5 spots depending on the tissue.
• 3.3. One of the histone subtypes, Hle, was found to be nonuniformly distributed within rabbit populations.
• 4.4. The prevailing fraction of animals had only a single spot of H1e (phenotype A). Approximately 10–28% of animals, depending on the breed, had two spots of H1e (e₁ and e₂; phenotype B) that slightly differed in the apparent molecular weights.
• 5.5. These two distinct gel patterns of H1e showed no tissue specificity, and the same phenotype was revealed in all tissues from the same animal.

     

A comparative study of the basic nuclear proteins from sperm of bivalve molluscs

• 1.1. Basic nuclear proteins from spermatozoa of the three mollusc species belonging to the class Bivalvia have been analyzed using one- and two-dimensional electrophoresis.
• 2.2. Four nuclear basic proteins have been purified and their amino acid compositions determined.
• 3.3. In these spermatozoa histone-type proteins coexist with protamine-like proteins.
• 4.4. The protamine-like proteins that have been studied show different electrophoretic behavior but in general are similar, with a high content of lysine, arginine, alanine and serine.
• 5.5. Interspecific variability has been found for the H1-like histone.

     

Purification and characterization of the protamines and related proteins from the sperm of a tunicate,Styela plicata

• 1.1. We have characterized for the first time the major sperm-specific nuclear proteins (X, P1 and P2) of the tunicate Styela plicata. Both P1 and P2 have an amino acid composition that allows us to classify them as protamine-like proteins.
• 2.2. The protein P1 of lower electrophoretic mobility has a trypsin-resistant core which is compositionally related to that of histones of the H1 family and to the PL-I protein found in the sperm of marine invertebrates. The evolutionary significance of this finding is discussed.
• 3.3. In addition to P1 and P2, the sperm nucleus of S. plicata contains a protein X component which is also compositionally related to PL-I proteins from bivalve molluscs.
• 4.4. Besides these sperm-specific proteins, a full complement of somatic-like histones, including a somatic-like histone H1, is also present. These histones represent only a small fraction of the total nuclear proteins of the sperm.

     

Monoclonal antibodies prepared against heparin lyase I and their reactivity toward heparin lyase I,II and III

• 1.1. Six different monoclonal IgG mouse antibodies to heparin lyase I from Flavobacterium heparinum were prepared.
• 2.2. The monoclonal antibodies were used to detect heparin lyases I, II and III by dot-blotting immunoassay and by Western blotting.
• 3.3. Individual antibodies showed different reactivity toward the three heparin lyases.
• 4.4. The reactivity of two of the monoclonal antibodies was destroyed by exposing heparin lyases to sodium dodecyl sulfate.
• 5.5. The antibodies can be used to rapidly distinguish between the three heparin lyases.

     

Comparative study of hemoglobins from different Artemia populations. The influence of temperature on the oxygen equilibria

• 1.1. The P50 values of extracellular hemoglobin (Hb) of five Artemia populations from different geographical origin are affected by temperature.
• 2.2. The free oxygen binding energy is high for all the populations (ΔH between −34.7 and −56.2kj/mol).
• 3.3. A possible correlation between thermal sensitivity of Hb and the ambient temperature of the habitat must be considered very carefully.
• 4.4. The occurence of different quantities of Hb1 (αα chains) Hb2 (αβ chains) and Hb3 (ββ chains) in the different populations possibly influences thermal sensitivity.

     

Selective effect of melatonin on the proliferation of lymphoid cells

• 1.1. The present study was designed to investigate the effect of melatonin on the proliferation of normal lymphocytes and certain T-lymphomas and myelomas under in vitro conditions.
• 2.2. The results revealed that administration of 200 μM melatonin inhibited significantly the incorporation of [³H]thymidine into both normal mouse and human lymphocytes and T-lymphoblastoid cell lines.
• 3.3. On the contrary, melatonin provoked an increase of myeloma cell proliferation.
• 4.4. The influence of melatonin on hybridoma cell lines was negligible.
• 5.5. Collectively, these data demonstrated that the chief pineal indole affect selectively the processes of lymphoblastoid cell growth.

     

A relationship between circulating natural glucocorticoids and the mechanical responses of the heart in atricial and precocial rodents

• 1.1. A comparison was made of the mechanical performance of heart muscle from mouse, an atricial mammal, with corticosterone as glucocorticoid and spiny mouse (Acomys cahirinus), a precocial mammal, with cortisol as glucocorticoid.
• 2.2. Force-frequency responses were negative in mouse and positive in spiny mouse.
• 3.3. During recovery, there was a gradual increase and an overshoot in the mouse, while in the spiny mouse there was an initial enhanced response, diminishing gradually with time.
• 4.4. High calcium concentration inhibited contractile tension in mouse heart, while it was positively inotropic in spiny mouse heart. Changes in the concentration of calcium did not change the patterns of force-frequency response.
• 5.5. Lowering the experimental temperature increased the time course and amplitude of the tension curve. However, various parameters exhibited different temperature sensitivity.
• 6.6. There was a significant difference in the levels of circulating cortisol between male and female spiny mice.
• 7.7. It is proposed that the differences in the mechanical responses of mouse and spiny mouse hearts may be explained in terms of the effects of the specific glucocorticoid hormone on the development of the sodium-calcium exchanger.

     

Is the metal binding protein metallothionein present in the coelenterate Hydra attenuata?

• 1.1. Studies have been performed on untreated and heavy metal treated Hydra attenuata in order to reveal the presence of low mol. wt metal-binding proteins.
• 2.2. A prepared rat metallothionein (Mt) standard, gel permeation, polyacrylamide gel electrophoresis and autoradiographic techniques were used in the experiments.
• 3.3. Our results indicate that H. attenuata, and three species of marine coelenterates, lack metallothionein (Mt) or other metal binding proteins.

     

A starvation test to determine optimal salinities for larval freshwater prawns,Macrobrachium rosenbergii

• 1.1. A starvation test was conducted in small beakers with stage 1 (S1) and stage 2 (S2) Macrobrachium rosenbergii larvae to determine optimal salinities.
• 2.2. Experiments were first performed with S2 larvae at 13 ppt to identify a suitable medium made with artificial sea salts.
• 3.3. A broad-range (0–35 ppt) and a subsequent narrow-range (9–16 ppt) salinity experiment with S2 larvae were used to identify 13 ppt as the optimal salinity, with 12 ppt as the next best; this agrees well with most previous estimates of optimal salinities for rearing larvae.
• 4.4. S1 larvae were also tested in a narrow-range salinity experiment but were not used further because, unlike starved S2 larvae, they molted during the experiment.
• 5.5. Identification of the optimal salinity was not affected by 50% daily water exchange or by bright light.
• 6.6. Exposure of larvae to three different salinities—7, 13 and 19 ppt—during S1 influenced the width of the optimal salinity range for S2 larvae.

     

Microheterogeneity of late histones in larval stages of sea urchin development

• 1.1. The total histone complement of early plutei were compared with that of intermediate and late larvae of the sea urchin Tetrapygus niger.
• 2.2. Electrophoretic comparison indicates that there are quantitative and qualitative shifts of the five classes throughout late larval development.
• 3.3. The strong similarity in the amino acid composition of total histones isolated from early, intermediate and late plutei indicates that the observed electrophoretic heterogeneity is due to post-translational modifications.

     

Purification and partial characterization of 200 kDa oncofetal antigen from radiation induced murine lymphocytic lymphoma

• 1.1. A 200 kDa glycoprotein (gp200) oncofetal antigen was purified from solubilized membranes of a radiation-induced murine lymphomcytic lymphoma cell line (XR11-5T), grown in syngeneic RFM mice, by successive gel chromatography of the active fraction on lentil lectin agarose, Q- and S-Sepharose and Superose-12 using an FPLC system.
• 2.2. A murine monoclonal antibody 115, produced by the syngeneic immunization of adult male C57BL/6N mice with 12-day mouse fetal cells, was used in a slot blot antibody assay to follow up the active fractions.
• 3.3. The purified glycoprotein has a pi of 5.4.
• 4.4. Treatment of radiolabeled gp200 with neuraminidase caused a slight reduction in size due to the removal of sialic acid groups and a shift in pI to 6.3.
• 5.5. Treatment of gp200 with different glycosidases shows that gp200 is susceptible to N- and O-glycanase but not to endoglycosaminidase H.
• 6.6. On extraction of gp200 with Triton X-114 it partitions exclusively into the detergent-rich fraction consistent with being an integral membrane protein.

     

The yolk polypeptides of a free-living rhabditid nematode

• 1.1. The yolk proteins of hermaphrodite Dolichorhabditis sp. (Nematode, Rhabditida) are composed of at least three polypeptides: VT1, VT2 and VT3 with molecular masses of 175.2, 107 and 82 kDa respectively.
• 2.2. All three yolk polypeptides make up at least one native protein complex which can be resolved by PAGE.
• 3.3. The yolk proteins are glycosylated and can be isolated by chromatography in Con A-Sepharose.
• 4.4. Partial chymotryptic hydrolysis shows that VT2 in different from its C. elegans homologue, YP115.
• 5.5. The main polypeptides synthesized by whole animals are the yolk components which are actively secreted in the incubation medium.

     

Mitogenic activity and immunological properties of bolesatine,a lectin isolated from the mushroom Boletus satanas Lenz

• 1.1. A lectin has been purified from the mushroom Boletus satanas Lenz.
• 2.2. The protein, called bolesatine, is mitogenic for human T lymphocytes in a dose- and time-dependent manner.
• 3.3. Optimal mitogenic doses induce the release of interleukin-1α and interleukin-2 from mononuclear cell cultures.

     

Lipid components and utilization in consumers of a seagrass community: An indication of carbon source

• 1.1. The lipid components of three animals, the rock crab Nectocarcinus integrifons, the rock flathead Platycephalus laevigatus and the southern garfish Hyporhamphus melanochir, feeding in the seagrass beds at Corner Inlet, Victoria, Australia have been examined in detail in order to provide further information on seagrass community structure.
• 2.2. Biological marker compounds detected within animal gut content material were used to recognize dietary sources and then utilized by community members.
• 3.3. Both H. melanochir and N. integrifons have been shown to ingest and to varying degrees incorporate seagrass lipid material, thus further confirming the importance of seagrass carbon in the Corner Inlet environment.
• 4.4. The southern sea garfish H. melanochir is observed to remove C₁₈ PUFAs (polyunsaturated fatty acids) from ingested seagrass material.
• 5.5. Seagrass sterols are altered during incorporation into the lipids of this fish.
• 6.6. Lipid-rich digestive juices play a role in the digestive processes of all three animals.
• 7.7. Components tentatively identified as (NMI) (non-methylene interrupted) fatty acids have been detected in the lipids of the garfish H. melanochir and the crab N. integrifons.
• 8.8. The fecal material of all three animals represent possible sources of these lipids (NMI acids) in Corner Inlet sediments.
• 9.9. Based on lipid compositional data, N. integrifons feeds on Posidonia australis detritus and associated epiphyte material.
• 10.10. The removal of both plant and epibiota cellular lipids along the digestive tract of the crab was observed, although structural components such as long chain mono- and α,ω-dicarboxylic acids, which have been previously recognized as seagrass marker lipids are not directly absorbed.

     

1H NMR study of metabolic alterations in the small intestine of rats infected with Hymenolepis diminuta

• 1.1. 1H NMR spectra of the duodenum, jejunum and ileum tissues of the small intestine of a rat showed metabolic gradients.
• 2.2. The concentrations of metabolites in these gut regions were altered by the presence of the tapeworm Hymenolepis diminuta.
• 3.3. In the infected duodenum there was significantly less glycogen, glucose and phosphocreatine/creatine, but significantly more lactate than in the corresponding controls.
• 4.4. Infected jejunum contained significantly less betaine but significantly more succinate, alanine and lactate.
• 5.5. Infected ileum had significantly less glycogen and taurine but significantly more alanine and lactate.

     

A new glutamate dehydrogenase from Halobacterium halobium with different coenzyme specificity

• 1.1. Halobacterium halobium has two chromatographically distinct forms of glutamate dehydrogenase which differ in their thermolability and other properties. One glutamate dehydrogenase utilizes NAD, the other NADP as a coenzyme.
• 2.2. The NADP-specific glutamate dehydrogenase (EC 1.4.1.4) was purified 65-fold from crude extracts of H. halobium.
• 3.3. The Michaelis constants for 2-oxoglutarate (13.3 mM), ammonium (3.1 mM) and NADPH (0.077 mM) indicate that the enzyme catalyzes in vivo the formation of glutamate from ammonium and 2-oxoglutarate.
• 4.4. The amination of 2-oxoglutarate by NADP-specific glutamate dehydrogenase is optimal at the pH value of 8.0–8.5. The optimal NaCl or KCl concentration for the reaction is 1.6 M.
• 5.5. None of the several metabolites tested for a possible role in the regulation of glutamate dehydrogenase activity appeared to exert an appreciable influence on the enzyme.
• 6.6. NAD- and NADP-dependent glutamate dehydrogenases from H. halobium showed apparent molecular weights of 148,000 and 215,000 respectively.

     

Purification and properties of tetralysine endopeptidase from Escherichia coli AJ005

• 1.1. A new tetralysine endopeptidase from Escherichia coli AJ005 has been purified about 135-fold.
• 2.2. The peptidase seems to be specific to tetralysine among lysine homopolymers.
• 3.3. The optimal pH was about 7.5
• 4.4. The activity was inhibited by KCN but not inhibited by soybean trypsin inhibitor.
• 5.5. The apparent K_m value was 2.5 × 1O⁻³ M for tetralysine.