The biochemical and energetic composition of somatic body components of echinoderms from the northern Gulf of Mexico

• 1.1. The biochemical and energetic compositions of the somatic body components of seven species of asteroids, one ophiuroid, and four echinoids from the northern Gulf of Mexico (30–95 m depth) were ascertained.
• 2.2. Levels of ash were high (68.5–90.8% dry wt) in all body-wall tissues, with the exception of the asteroid Echinaster modestus (51.6% dry wt). Levels of ash were low in the pyloric cecae (nutrient storage organ) of asteroids (4.6–30.8% dry wt).
• 3.3. Levels of lipid (8.1–34.5% dry wt), soluble protein (15.9–28.7% dry wt), and insoluble protein (18.1–48.6%, dry wt) were high in the pyloric cecae of all asteroids, but generally low in ophiuroid and echinoid body-wall tissues. High protein levels (28.5–44.5% dry wt) in the body-wall of the asteroids Echinaster modestus and Anthenoides pierceisuggest it may play a role in nutrient storage.
• 4.4. All somatic tissues contained low levels of carbohydrate (0.2–1.4% dry wt).
• 5.5. Levels of energy in pyloric cecal tissues (12.99–26.05 kJ/g dry wt) were 4–8 times higher than in echinoderm body-wall tissues (2.92–11.91 kJ/g dry wt).
• 6.6. The biochemical and energetic compositions of echinoderms from the northern Gulf of Mexico are similar to those of species from other latitudes and depths.

     

Changes in composition and proteolytic enzyme activities of artemia during early development

• 1.1. The proximate composition, total and free amino acids, and proteases of Artemia nauplii were determined during early development.
• 2.2. Moisture increased from 71.0% to 80.8%, crude protein decreased from 13.2% to 8.8%, crude fat and ash varied slightly.
• 3.3. The total amino acids decreased. Free amino acids changed in three patterns.
• 4.4. Trypsin, chymotrypsin, carboxypeptidase A, B and cathepsin B and C increased in activity. The activity of trypsin was lower, while cathepsin B and C were the highest.
• 5.5. The protease activities were maximal at pH 7.5 and 8.0, and at 45°C on casein.
• 6.6. The optimal pH for carboxypeptidase A was 4.0, for carboxypeptidase B was 4.5, for trypsin and chymotrypsin were 7.0–7.5. The protease(s) active at pH 9.0–9.5 were to be determined.

     

Influence of temperature,rate of feeding and body weight on nitrogen metabolism of bream,Abramis brama L

• 1.1. Measurements of the rate of nitrogen consumption, total nitrogen and ammonia excretion and nitrogen absorption of bream, Abramis brama L. (body weight range 0.4–519 g wet wt) were made at 10, 15 and 20 C.
• 2.2. Fish were fed once daily on live zooplankton collected in Lake Balaton and cultured Tubifex sp. at 5–15% of their body weight.
• 3.3. Fish size and temperature had a combined effect on the rate of total nitrogen excretion. Total nitrogen excretion did not increase proportionally with an increase in consumption.
• 4.4. On average, 52–80% of the nitrogen consumed with food was excreted by bream.
• 5.5. The greatest part of total nitrogen excretion was ammonia and its proportion in the total ranged between 53 and 75%.
• 6.6. Temperature did not have any significant effect on the proportion of excreted ammonia and the rate of excreted total nitrogen was the only factor determining its proportion in the total.
• 7.7. The rate of nitrogen absorption of bream was surprisingly very high.

     

Heterosynthetic origin of the major yolk protein,vitellin, in a nereid,Perinereis cultrifera (polychaete annelid)

• 1.1. An examination of proteins synthesized by Perinereis cultrifera oocytes incubated in vitro with [³H]leucine clearly shows that these cells are not capable of synthesizing the main yolk protein previously identified in this worm.
• 2.2. In addition, the detection of radiolabelled vitellin in oocytes after in vitro incubation of an oocyte-coelomocyte cell mixture in presence of [³H]leucine strongly suggests that the coelomocytes, free cells in the coelomic cavity, synthesize and secrete a vitellin precursor, vitellogenin, that is subsequently taken up by the oocytes.
• 3.3. Two native proteins differing in mol. wt but reacting with anti-vitellin antibodies have been identified in coelomocyte incubation medium. Also found in the coelomic fluid, they have been designated VG1 (M_r = 530,000) and VG2 (M_r = 320,000).
• 4.4. The two vitellogenins consist of a single type of polypeptide of M_r = 176,000 and are incorporated in the oocytes where they are apparently observed under a single molecular form corresponding to VG1, the highest mol. wt protein similar in size to the initial form of vitellin (VI, 530,000).
• 5.5. From these data, it seems likely that VG2 is a monomeric molecule that is taken up by the oocytes as a dimer of VG1.
• 6.6. We conclude that P. cultrifera accumulates vitellin heterosynthetically and that vitellogenin is produced by the coelomocytes. Moreover, a single polypeptide similar in size to the polypeptidic component of secreted vitellogenin has been detected in the coelomocytes.
• 7.7. Since this polypeptide has been identified previously as the single intraoocytic precursor of the four lower mol. wt products that make up the mature form of vitellin (V5), it appears that P. cultrifera exhibits for vitellogenin a processing pathway in which cleavage of the precursor occurs only after uptake by the oocyte.

     

Growth and haematological response of sturgeon hybrids Russian sturgeon (Acipenser guldenstadti brandt) × beluga (Huso huso L.) to protein and lipid contents in the diet

• 1.1. Fingerlings of intergenious hybrid Russian sturgeon (Acipenser guldenstadti) × beluga (Huso huso) weighing 22 g reared in water with salinity 18 ppt were fed nine diets differing in protein and fat content.
• 2.2. The increase of dietary protein content (from 45 to 52%) improved the fingerlings growth rate, food and protein conversion efficiencies. No effect of further protein content increase to 60% was observed.
• 3.3. The increase of dietary fat content from 10 to 20% positively influenced all growth results.
• 4.4. The muscular lipid content increased following the increase in dietary fat due to accumulation of triacylglycerols.
• 5.5. Distinctive leucopenia in neutrophils and leucophilia in lymphocytes following dietary protein and fat content increase were observed.
• 6.6. It was concluded that within the analysed range of values the increase of dietary protein and lipid content improved the physiological status of sturgeon hybrid fingerlings.

     

Molecular and spectroscopic characterisation of a low molecular weight seed storage protein from yellow mustard (Sinapis alba L.)

• 1.1. A 1.7S protein has been purified from mustard seeds (Sinapis alba L.). This protein, soluble in water and dilute salt solutions, is considered as an albumin and constitutes about 10% of the total soluble protein in mustard seeds.
• 2.2. Its molecular weight is approximately 15,000 and is composed of two polypeptide chains (M_r = 9500 and 5000), linked by two disulfide bridges.
• 3.3. The amino acid compositions of both subunits as well as of the native protein are reported, showing a strong homology with napins from Brassica napus L.
• 4.4. The ultraviolet absorption, fluorescence emission and circular dichroism spectra of the purified protein have been obtained. The mustard protein exhibits about 50% α-helix with a very low β-structure content. Based on its structural characteristics, a zein-like packing is proposed for this protein from mustard seeds.

     

Some physical and chemical properties of purified nematocysts of Hydra attenuata pall. (Hydrozoa,cnidaria)

• 1.1. A method for purifying undischarged nematocysts from Hydra and other cnidarians is described.
• 2.2. Isolated cysts (relative densities 1.22–1.24) evaginate their tubular content even after previous dehydration.
• 3.3. The cyst wall is permeable to dyes of mol. wts up to 600,000.
• 4.4. Approximately two-thirds of the cyst's dry wt are soluble proteins. Eighty per cent of them are of low mol. wt and highly anionic, presumably serving as binding sites for Ca²⁺ and Mg²⁺.
• 5.5. The other 20% includes 30 different proteins amongst them toxins and enzymes (phospholipase and little proteases but no collagenase, chitinase or hyaluronidase).

     

Detection of 180 kDa proteins in electroplax sodium channel preparations

• 1.1. Co-isolating proteins (M_r 170,000–220,000) from sodium channel preparations made from the electric organ of the electric eel (Electrophorus electricus) were detected on Western blots using monoclonal a antibodies.
• 2.2. Similar protein patterns were seen on immunoblots containing immunoprecipitated protein from eel muscle and brain tissues but not heart.
• 3.3. These co-isolating proteins could be separated from the mature TTX-sensitive channel protein (M_r 280,000) using a lentil lectin-Sepharose column.
• 4.4. The 180 kDa proteins do not appear to be channel-related and can be detected as contaminants in electroplax sodium channel preparations using the monoclonal antibodies described here.

     

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.

     

Crystalline style proteins from bivalve molluscs

• 1.1. Proteins from crystalline styles of twelve species of bivalve mollusc were examined under different gel electrophoresis conditions and stained to reveal both protein and carbohydrate.
• 2.2. Native extracts of styles produced relatively few protein bands, however denaturation with SDS resulted in much more complex zymograms.
• 3.3. All species possessed several prominent high mol wt glycoproteins.
• 4.4. Eulamellibranchia all had a major non-glycosylated protein at approx. 62,000 mol. wt.
• 5.5. Most Filibranchia had a major non-glycosylated protein at 37,000–50,000 mol. wt.
• 6.6. Eulamellibranchia were a much more homogeneous group than the Filibranchia.

     

Carbohydrate metabolism in several tissues of rainbow trout,Oncorhynchus mykiss,is modified during ovarian recrudescence

• 1.1. Several pathways of carbohydrate metabolism were evaluated in three different tissues—liver, gonad and kidney—of a hatchery-reared population of rainbow trout (Oncorhynchus mykiss) which characterised two different stages of their gonadal maturation, i.e. previtellogenesis and established exogenous vitellogenesis.
• 2.2. A fall in liver glycogen levels was observed during exogenous vitellogenesis. A decrease in activity of the enzymes involved in glycolysis and in the pentose phosphate shunt was also observed, suggesting that at the end of exogenous vitellogenesis the necessity of energy and reducing power has decreased compared to the situation at the onset of this period.
• 3.3. The main changes observed in gonad during vitellogenesis were the decreased activity of glycolysis and the pentose phosphate shunt as well as increased glycogen levels. The stored glycogen should be used later in association with the embryo development.
• 4.4. No major changes were observed in kidney metabolism throughout the vitellogenic process.
• 5.5. Exogenous vitellogenesis in rainbow trout is mainly associated with increased glycogen levels in the gonad and decreased metabolic activity in the liver.

     

Identification and partial characterization of plasma membrane polypeptides of Crithidia guilhermei,crithidia deanei and Crithidia oncopelti

• 1.1. Components of the cell surface of Crithidia guilhermei, Crithidia deanei and Crithidia oncopelti were radioiodinated by the iodogen technique. The distribution of proteins in the detergent-poor (DPP) and detergent-enriched phase (DRP) were studied using a phase separation technique in Triton X-114 and one- and two-dimensional polyacrylamide gel electrophoresis in sodium dodecyl sulphate (1D and 2D SDS-PAGE).
• 2.2. Significant differences were noted in the proteins present in the DRP when the three species were compared.
• 3.3. Two major bands with mol. wt 28,000 and 56,000 and motility in the pH gradient of 7.4 and 6.3, respectively, were observed in C. guilhermei, but not discernible in C. deanei and C. oncopelti.
• 4.4. One polypeptide with mol. wt 50,000 and p1 4.9 was identified in the DRP of C. deanei.
• 5.5. A broad band with mol. wt 68,000–140,000 and pI 4.7–5.5 was clearly observed in the DRP of C. deanei and one or two polypeptides only present in the DPP were observed in the three Crithidia species analyzed.
• 6.6. Our observations show that C. guilhermei has characteristic surface polypeptides not found in C. deanei and C. oncopelti.
• 7.7. Our results, in association with those reported by others, show that the phase separation using Triton X-114 offers a simple approach to the separation and further analysis of a select group of proteins from the bulk of the cellular proteins.

     

Accumulation,distribution and toxicity of selenium in the adult house fly,Musca domestica

• 1.1. Accumulation and distribution of dietary Se in relation to mortality was investigated in adult house flies.
• 2.2. The midgut preferentially accumulated Se and thereby limited toxicity.
• 3.3. Midgut Se concentrations were from 6- to 107-fold higher than in carcass, and from 15 to 71% of the total Se was associated with midgut.
• 4.4. When dietary levels of Se were raised the midgut saturated at 15 μg Se/g tissue, followed by a rise in carcass levels to greater than 0.5 μg Se/g tissue and increased mortality.
• 5.5. Se levels in lysosomal fractions were from 3- to 50-fold higher than in other subcellular fractions, suggesting that Se is sequestered in lysosomes.
• 6.6. Se added to drinking water was toxic at 4–8 ppm.

     

Neurohypophysial hormones as molecular evolutionary tracers: investigations on the sturgeons Acipenser stellatus and Acipenser guldenstadti

• 1.1. Neurohypophysial hormones of two sturgeon species, Acipenser stellatus and Acipenser guldenstadti, have been purified through molecular sieving on Bio-Gel P4 and reverse-phase high pressure liquid chromatography on Nucleosil C18 columns.
• 2.2. Arginine vasotocin has been identified in both species by its retention time in partition chromatography, amino acid composition and, in the case of A. stellatus, by amino acid sequencing.
• 3.3. A second peptide has been purified and could be α-deamidated vasotocin.
• 4.4. Another peptide with oxytocic activity, distinct from the known oxytocin-like peptides, seems to be present in very small amounts.

     

The reproduction strategy of oyster ostrea edulis L. from the biochemical point of view

• 1.1. Influence of the biochemical composition of food (four species of micro-algae and one mixture) on the biochemical composition of gonads and larvae of O. edulis (total protein, lipid, carbohydrate, ash content, neutral and polar lipid class composition, amino acid composition and fatty acid composition of total, neutral and polar lipids) and the size of newly released larvae have been investigated.
• 2.2. Precentage of total lipids and triacylglycerols in gonads depends on that in algae (r = 0.52 and 0.69 accordingly).
• 3.3. Gonads rich in lipids had a higher level of triacylglycerols, phospholipids, polar lipids and a lower value of the ratio phosphatidylethanolamine/phosphatidylcholine (PE/PC) than gonads with a low lipid content.
• 4.4. Amino acid composition of gonads depends on that of food, in this case, essential acids are preferentially accumulated (Asp acid, Ser, Ala, Cys, Tyr and Pro) and two non-essential (Thr and Lys).
• 5.5. Fatty acid composition of total lipids of gonads was rather stable; except for the two essential acids 20:523 and 22:6w3, their percentage depends on that of food r = 0.65 and 0.65 accordingly). Fatty acid composition of neutral lipids was more diverse (in number and degree of variety) as compared to polar lipids.
• 6.6. Larvae released from oysters with gonads rich in lipids had a higher percentage of lipids, triacylglycerols, size and a lower ash percentage and value of ratio PE/PC, as compared to larvae from gonads with low lipid content. Total lipid and triacylglycerol contents in gonads correlate rather well with those in larvae (r = 0.77 and 0.47 accordingly).
• 7.7. Phospholipid class composition of larvae strongly depends on that of gonads. All the correlations are high and positive in character (except for phosphatidylinositol).
• 8.8. Amino acid composition of larvae depends on that of gonads and, as in the case with gonads, the same essential acids are accumulated in the first place.
• 9.9. Fatty acid composition of total lipids of newly released larvae was rather stable and independent on that of gonads except for total polyunsaturated acids (r = 0.70) and 20:5w3 (r = 0.65). Fatty acid composition of neutral lipids was lesser diverse (in number and degree of variation) as compared to polar lipids.

     

A quantitative method for analysis of radiolabelled proteoglycans synthesized by cultured human arterial smooth muscle cells

• 1.1. Sulphate labelled proteoglycans (PG) synthesized by cultured human arterial smooth muscle cell have been quantified using an improved method based on a combination of specific enzymes and ethanol precipitation.
• 2.2. The present method gives quantitative data of PGs and subclasses allowing batchwise analysis of a large number of samples.
• 3.3. Approximately 81 % ± 1.7% (mean ± SD, n = 6) of total PGs synthesized by human arterial smooth muscle cells accumulated in medium.
• 4.4. In cell layer and medium chondroitin sulphate proteoglycan constituted 65.0% ± 0.3% and 75.8% ± 0.7% (mean ± SD, n = 3), respectively of sulphated PGs.
• 5.5. Heparan sulphate proteoglycan accounted for 26.8% ± 0.6% in cell layer and 22.6% ± 0.5% (mean ± SD, n = 3) in medium of sulphated PGs.

     

A novel inhibitor of glycogen phosphorylase from crayfish hepatopancreas

• 1.1. A novel glycogen phosphorylase inhibitor was partially purified from crayfish hepatopancreas.
• 2.2. The inhibitor was found only in two species of crayfish examined, and not in lobster, fresh and salt water clams, mussels or cockroaches.
• 3.3. The inhibitor is a small protein (M_r = 23,000) which did not show proteolytic activity.
• 4.4. Preliminary kinetic analysis of the inhibitory mechanism indicated that it bound to both glycogen and the glycogen phosphorylase protein.
• 5.5. Inhibitor binding to glycogen resulted in a competitive inhibition pattern with respect to glycogen phosphorylase (inhibition constant of ca 10 μg/ml).
• 6.6. The inhibitor also bound glycogen phosphorylase directly with a binding coefficient of 100 μg/ml resulting in a partially non-competitive inhibition pattern with respect to phosphate.

     

Comparative study of the endemic freshwater fauna of lake baikal—I. Phospholipid and fatty acid composition of two mollusc species,Baicalia oviformus and Benedictia baicalensis

• 1.1. Lipid and phospholipid compositions of endemic freshwater molluscs belonging to the class Gastropoda, Baicalia oviformus and Benedictia baicalensis, were studied.
• 2.2. The fatty acids composition of total lipids, neutral, glyco- and phospholipid fraction was investigated by capillary gas chromatography-mass spectrometry.
• 3.3. Ninety-five fatty acids were identified: 23 saturated (both iso- and anteiso-), 28 monoenoic, 14 dienoic and 30 polyenoic.
• 4.4. High percentage of the two main acids, 18:4 and 18:4(n-3) in phospholipid and glycolipid fractions were identified.
• 5.5. A number of unusual polyunsaturated fatty acids, such as 19:4, 18:5(n-3), 24:4(n-6), 24:5(n-6), 24:6(n-3), and furanoid acids, were found.

     

Variations in the levels of progesterone in Mytilus edulis during the annual reproductive cycle

• 1.1. Progesterone levels in Mytilus edulis males and females during the annual reproductive cycle were analysed in the whole animal and in the gonads using gas-liquid chromatography and radioimmunoassays.
• 2.2. The high hormone levels in the whole animal were observed in July and October, coincident with the main spawning seasons.
• 3.3. The levels of progesterone in gonad extracts also show a maximum in summer (July).
• 4.4. The patterns of the progesterone levels in males and females throughout the annual reproductive cycle are similar.
• 5.5. These data are discussed in relation to the role of progesterone in the regulation of sex-specific processes, particularly gametogenesis.

     

Seasonal changes in condition and lipids composition of the bivalve Macoma balthica L. from the gulf of Gdańsk (Southern Baltic)

• 1.1. The total lipids content and composition of lipid classes, their per cent in dry wt of soft tissues and level in standard animal, as well as composition of fatty acids and sterols were studied in Macoma balthica collected from three sites in the Gulf of Gdańsk, in the years, 1983–1984.
• 2.2. The increase in the content of total lipids, triacylglycerols, oleopalmitic, 16:1 and eicosapentaenoic acids, 20:5, C27 sterols (mainly cholest-5en-3β-ol), in spring and early summer and their decrease in autumn and winter were observed.
• 3.3. Content of phospholipids, sterols and hydrocarbons in the tissue dry wt of Macoma balthica remained nearly constant.