A dopamine- and octopamine-sensitive adenylate cyclase in the nervous system of Octopus vulgaris

• 1.1. Adenylate cyclase activity was assayed in the optic lobe of Octopus vulgaris.
• 2.2. Both octopamine and dopamine stimulate the octopus adenylate cyclase, apparently by competing with the same receptor site.
• 3.3. (±)-2-Amino-6,7-dihydroxy-1,2,3,4-tetrahydronaphthalene-HBr (6,7-ADTN) and a number of phenylethanolamine derivatives stimulate the octopus adenylate cyclase activity.
• 4.4. The dopamine D-1 antagonists R(+)-7-chloro-8-hydroxy-3-methyl-1-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine-HCl (SCH-23390) and (±)-7-bromo-8-hydroxy-3-methyl-1-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine-HCl (SKF-83566) are unable to antagonize the effects of dopamine and octopamine, and similarly ineffective is the agonist (±)-1-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine-7,8-diol-HCl (SKF-38393).
• 5.5. No detectable binding of labelled SCH-23390 occurs on membrane preparations from octopus optic lobe.

     

The isolation of a plasma membrane-rich fraction from the skeletal muscle of two species of marine crab,Carcinus maenas and Cancer pagurus

• 1.1. A rapid method for the isolation of a plasma membrane-rich fraction from crab leg muscle, with high purity and yield recovery was developed.
• 2.2. The method is based on sodium iodide extraction of the crude homogenate, followed by centrifugation on Percoll self-creating gradient.
• 3.3. (Na⁺K⁺)ATPase and alkaline phosphodiesterase I were used as marker enzymes for the plasma membrane and revealed levels of purification of approximately 13-fold and yields recovery of the total activity in the crude muscle homogenate of approximately 18%, for both species of crab studied.

     

Purification and some properties of elastase from hepatopancreas of king crab Paralithodes camtschatica

• 1.1. Elastase has been purified from the hepatopancreas of the king crab (Paralithodes camtschatica). Specific activity of the enzyme measured toward Suc-(Ala)₃-pNA and Boc-(Ala)₃-pNA was 926 and 3700 mUnits per mg of protein, respectively.
• 2.2. The enzyme is an anion protein (pI 4.5) with an approximate mol.wt of 28.5 kDa.
• 3.3. The enzyme exhibited a bell-shaped pH-dependence for the hydrolysis of Suc-(Ala)₃-pNA with a maximum at 8–8.5. Under these conditions the values of K_m and k_cat of the crab elastase are 4 mM and 4.75 s⁻¹, respectively.
• 4.4. The serine elastase is effectively inhibited by elastinal and diisopropylfluorophosphate.
• 5.5. It is shown that some salts except HgCl₂ activate the protease. In the presence of HgCl₂ with concentrations of 10 mM and higher, the crab elastase is inactive. SDS and Triton X-100 have no any effect on the activity of crab elastase.

     

Purification and characterization of lipoprotein lipase from the white adipose,skeletal muscle,cardiac muscle,mammary gland and lung tissues of the rat

• 1.1. Lipoprotein lipase (LPL) was isolated from five rat tissues: white adipose, skeletal muscle, cardiac muscle, mammary gland and lung.
• 2.2. Specific activity of the preparations varied from 75 U/mg for skeletal muscle and 720 U/mg for adipose.
• 3.3. The preparations were further analysed using SDS-PAGE and a single component identified. The mol. wt of 61,000 Da of this component was consistent for all five of the tissue sources.
• 4.4. Significant differences in the values of the isoelectric points of the enzyme species were revealed. The values varied from 7.23 (SEM 0.022) for cardiac and lung to 7.51 (SEM 0.037) for mammary.
• 5.5. Two-dimensional electrophoresis, using isoelectric focusing in the first dimension and SDS-PAGE in the second revealed differences in the patterns of stained material derived from the five tissue sources.

     

Variation in turtle myoglobins (subfamily emydinae: Testudines) examined by isoelectric focusing

• 1.1. Myoglobins from heart and skeletal muscle of turtles were analyzed by thin-layer isoelectric focusing.
• 2.2. Within the subfamily Emydinae, variation in the occurrence of two myoglobin electromorphs (pI 6.8 and 6.9) was detected.
• 3.3. Patterns of myoglobin polymorphism support dividing the Emydinae into two subfamilies and help resolve controversial theories on relationships of the genus Deirochelys.
• 4.4. Possible adaptive significance of the myoglobin variants (isoforms) remains to be determined.

     

Purification and characterization of elastase from the pyloric caeca of rainbow trout (Oncorhynchus mykiss)

• 1.1. An elastase-like enzyme was purified from the pyloric caeca of rainbow trout by hydrophobic interaction, cation exchange and gel-filtration chromatography.
• 2.2. The approximate molecular weight of the elastase was 27 kDa and the isoelectric point was remarkably basic.
• 3.3. The pH optimum of this enzyme was 8.0, when assayed with Succinyl-Ala-Ala-Ala-p-Nitroanilide.
• 4.4. When assayed with Succinyl-Ala-Ala-Ala-p-Nitroanilide, the enzyme activity had a temperature optimum of 45°C, and the enzyme was stable up to this temperature.
• 5.5. The trout elastase exhibited a higher specific activity than porcine elastase against Succinyl-Ala-Ala-Ala-p-Nitroanilide and elastin-orcein.
• 6.6. The trout elastase was inhibited by elastatinal, PMSF, TPCK, SBTI and Bowman-Birk inhibitor.

     

Respiratory mechanisms and metabolic adaptations of an intertidal crab,Chasmagnathus granulata (Dana, 1851)

• 1.1. The ventilatory mechanism, gill area, sites of oxygen uptake, oxygen consumption and activity of a crab from south Brazil, Chasmagnathus granulata, were investigated.
• 2.2. The oxygen uptake seems to be restricted to the gill lamellae.
• 3.3. The gill area varies with the wet body weight, being relatively higher in smaller animals. There is not a significative reduction of the gill area in relation to species of the infralittoral zone.
• 4.4. C. granulata presents a mechanism for recirculating the water of its branchial chamber when exposed to atmospheric air.
• 5.5. The oxygen consumption and activity are reduced when the animals are exposed to atmospheric air. The reduction in the oxygen consumption may be related to the poorly adapted respiratory system, while the decrease in activity may be a mechanism for saving energy during this hypoxic period.

     

Identification of a glycoprotein complex containing a glycogen synthase isozyme in Ascaris Suum obliquely-striated muscle

• 1.1. A glycogen/protein complex which contains the major portion of glycogen synthase activity in Ascaris suum muscle has been purified.
• 2.2. The complex contains two proteins which can be dissociated from a glycoprotein component.
• 3.3. The glycoprotein contains glycogen-like domains and is resistant to trypsin digestion.
• 4.4. The glycogen synthase activity in the purified complex catalyzes glycogen synthesis in the absence of exogenous glycogen, but demonstrates an absolute glucose 6-phosphate requirement for activity.
• 5.5. The data support the hypothesis that this isozyme of glycogen synthase is significantly different from the cyclic AMP-regulated enzyme.

     

Skeleton weight-free oxygen consumption related to adaptations to environment and habits of six crustacean species

• 1.1. Oxygen consumption in six crustacean species from the continental shelf of the NW Gulf of Mexico was related to the ash free weight per dry weight (afdw) gram of the tissue excluding the exoskeleton, suggesting a close relationship to their life strategies.
• 2.2. Dry weight exoskeleton proportion varied among species, with highest values recorded in callapid brachyuran crab species (46.8–52.5%) against the values recorded in portunid crab (45.8–48%) and the shrimp species (26.7–35.7%).
• 3.3. Oxygen consumption was related to afdw in each species according to the expression y = ax^b, with b values ranging from 0.68 to 2.92.
• 4.4. Rates of oxygen consumption per afdw/dw were larger in shrimps than in portunids and callapids, and was related to the morphophysiology and lifestyle of six species described; the former as the morphological design of the exoskeleton versus the muscle content in the species and the latter as the activity rate in the environment.
• 5.5. The oxygen extraction efficiency, calculated from oxygen consumption, was higher in the eurytopic species Penaeus aztecus and Callinecies similis than in species restricted to the marine environment, hence considered as a response to environmental fluctuations.

     

Age-dependent proteins in eyes of annual killifishes Pterolebias longipinnis detected by 2-dimensional electrophoresis

• 1.1. Eye proteins of Pterolebias longipinnis have been analyzed by 2-dimensional isoelectric focusing SDS-polyacrylamide gel electrophoresis during aging from adolescence until normal death.
• 2.2. The protein pattern on the gels changed gradually with progressing age.
• 3.3. In senescent eyes, three protein spots appeared for a time and 36 disappeared from the pattern.
• 4.4. The isoelectric points of the proteins in the presence of urea and the molecular weights in an unreducing buffer are presented.

     

Isolation and characterization of phospholipase A2, from Agkistrodon bilineatus (common cantil) venom

• 1.1. Phospholipase A₂ was isolated from Agkistrodon bilineatus venom by Sephadex G-75 and CM-Cellulose column chromatographies.
• 2.2. The purified phospholipase A₂-I gave a single band on disc polyacrylamide gel electrophoresis, isoelectric focusing and sodium dodecyl sulfate polyacrylamide gel electrophoresis.
• 3.3. The enzyme preparation had a molecular weight of 14,000, isoelectric point of pH 8.77 and possessed 123 amino acid residues.
• 4.4. The purified phospholipase A₂ possessed lethal, indirect hemolytic and anticoagulant activities.
• 5.5. The enzyme hydrolyzed the phospholipids phosphatidyl choline (PC), phosphatidyl ethanolamine (PE), phosphatidyl inositol (PI) and phosphatidyl serine (PS).
• 6.6. The concentration of mouse diaphragm was inhibited and the contraction of guinea pig left atrium was increased by phospholipase A₂-I.
• 7.7. Phospholipase A₂ activity of this preparation was inhibited by ethylenediamine tetraacetic acid, p-bromo phenacyl bromide, n-bromo succinimide or dithiothreitol, but not by diisopropyl fluorophosphate or benzamidine.

     

Purification and partial characterization of an AMP deaminase from the marine invertebrate Palaemon serratus

• 1.1. AMP deaminase from Palaemon serratus tail muscle was partially purified by chromatography on cellulose phosphate.
• 2.2. Muscle homogenates expressed very low enzyme activities and the presence of ATP was necessary to detect AMP deaminase. The specific activity and substrate affinity of the purified enzyme were also very low.
• 3.3. The purified prawn muscle AMP deaminase was contaminated by contractile proteins, one of the major contaminants being actin.
• 4.4. The enzyme displayed a very high affinity for actomyosin which was only partially abolished by pyrophosphate.

     

Salinity tolerance of adult and juvenile red king crabs Paralithodes camtschatica

• 1.1. Juvenile king crabs were more tolerant of reduced salinities than adult crab; juvenile crab were better volume regulators at reduced salinities than adult crab.
• 2.2. Adult female king crab hemolymph was hyperosmotic to full seawater (30 ppt) and isosmotic to dilute seawater. Juvenile king crab (2 years old) were hypoosmotic at the same concentrations.
• 3.3. Lower osmotic concentration of juvenile hemolymph is at least partially due to lower sodium concentration.
• 4.4. Juvenile king crab can tolerate some dilution and survive for short periods in the reduced salinity of the lower intertidal zone.

     

Content and partial characterization of collagen in crustacean muscle

• 1.1. The collagen content in the abdominal muscle of seven species including shrimp, prawn, lobster and squilla varied among the species ranging from 1.1 to 6.2% of total tissue protein and the content in pereiopod and thoracic muscles of four species of crab varied ranging from 0.2 to 0.8%.
• 2.2. These results indicate that the musculature in flexible part comprises a high proportion of collagen.
• 3.3. The major collagen from the crustacean muscle was found to be similar to Type V collagen from the vertebrate muscle with respect to the solubility and amino acid composition.

     

Locust vitellogenin receptor: an acidic glycoprotein with N- and O-linked oligosaccharides

• 1.1. The locust vitellogenin (VTG) receptor which is embedded in oocyte plasma membranes is a glycoprotein.
• 2.2. With various lectins oligosaccharide units have been identified, among them neuraminic acid linked to Gal or GalNAc, mannose chains, Gal linked to GalNAc or GlcNAc and fucose linked to GlcNAc.
• 3.3. With specific enzymes it could be shown that mannose and most other oligosaccharides are O-linked while others like fucose are N-linked.
• 4.4. Enzymatic removal of all O-linked carbohydrates resulted in a drop of the molecular mass of the receptor protein from 200,000 to 110,000.
• 5.5. A total of N- and O-linked oligosaccharides of 54% was calculated.
• 6.6. The isoelectric point of the receptor was found to be at pH 3.4 increasing slightly after removal of neuraminic acid.
• 7.7. Removal of neuraminic acids destroyed the binding ability for VTG.

     

Electrophoretic characterization of a hybrid between Eretmochelys imbricata and Caretta caretta (Cheloniidae)

• 1.1. An intermediate morphotype between Eretmochelys imbricata and Caretta caretta was studied in Praia do Forte, Bahia, Brazil.
• 2.2. Three enzymatic systems were successfully analyzed: SOD, lactate dehydrogenase (LDH) and esterase (EST). Isoelectric focusing of total soluble proteins of muscle and transferrin were shown.
• 3.3. Esterase exhibited nine phenotype patterns, seven in C. caretta and one in the others morphotypes. SOD phenotypes were identical in the three morphotypes. Lactate dehydrogenase and transferrins were characteristic for each species.
• 4.4. Jaccard's measure of similarity was calculated and a phenogram with the three morphotypes were constructed using isoelectric focusing of total soluble proteins.

     

Biomines-stimulated phosphorylation and (Na+, K+-ATPase in the gills of the chinese crab,Eriocheir sinensis

• 1.1. Subcellular distribution of (NA⁺, K⁺-ATPase and ouabain-insensitive ATPase (Mg²⁺-ATPase) are compared in branchial tissues of the euryhaline crab, Eriocheir sinensis, acclimated to fresh water.
• 2.2. Both the anterior and posterior gills contain cAMP-dependent protein kinase and endogenous protein substrate for phosphorylation.
• 3.3. Phosphorylation occurs in both “particulate” and “soluble” subcellular fractions but its stimulation by cAMP is restricted to the “soluble” fraction.
• 4.4. serotonin (5-HT) and dopamine receptors are present only in the “light particulate” fraction isolated from the posterior gills.

• 1.(a) Serotonin and dopamine have no effect on the phosphorylation observed in a subcellular fraction alone.
• 2.(b) Activation of the phosphorylation by serotonin and dopamine is found when the soluble fraction (source of cAMP-dependent protein kinase) is added to the fraction P₃ from the posterior gills.
• 3.(c) No activation occurs with the fractions P₃ as well as P₁ or P₂ (not shown) from anterior gills of fresh water crab.
• 4.(d) Cyproheptadine, a serotonin receptor antagonist, inhibits the 5-HT dependent increase in phosphorylation.
• 5.(e) The dopamine receptor antagonist, chlorpromazine, inhibits dopamine-stimulated phosphorylation.
• 6.5. Ouabain mimics the effect of cyproheptadine on the serotonin-stimulated phosphorylation found in the posterior gills.

     

Effects of niacin deficiency on the relative turnover rates of proteins in various tissues of Japanese quail

• 1.1. The effects of niacin deficiency on the relative turnover rates of proteins in various tissues of Japanese quail were investigated.
• 2.2. The level of liver NAD was not affected by niacin deficiency whereas the level of pectoral muscle NAD was markedly reduced.
• 3.3. In all dietary treatments the liver had the highest turnover rates of proteins, heart and brain had intermediate rates, and pectoral muscle had the lowest rates.
• 4.4. Relative turnover rates of proteins in all tissues (particularly pectoral muscle) of the niacin deficient group were significantly higher than those of pair-fed control group, although there were no significant differences in turnover rate between pair-fed control and control groups.
• 5.5. The high turnover rate of proteins in niacin deficiency was primarily attributed to enhanced degradation rate of proteins rather than enhanced synthesis rate of proteins.
• 6.6. Optical density scanning (or densitometric) of water-soluble pectoral muscle proteins separated by isoelectric focusing revealed several additional minor protein bands between major protein bands in the niacin deficient group which were more pronounced in the acidic region of the gel.
• 7.7. These results suggest that proteins with a low pI value in pectoral muscle of the niacin deficient animal are highly sensitive to protein degradation.

     

Myofibril and sarcoplasmic reticulum changes during muscle development: Activity vs inactivity

• 1.1. The purpose of this study was to determine whether biochemical changes of skeletal muscle that occur as a result of exercise in young rats persist into adulthood.
• 2.2. Littermates (10 days old) were assigned to a 3, 6 and 12 week control or training group. In addition, a rest-exercise group (R-E) and exercise-rest (E-R) group were included.
• 3.3. The rest-exercise and exercise-rest rats were maintained for the 12 weeks with the first 6 weeks being either rest or exercise and the condition reversed during the last 6 weeks of the experiment.
• 4.4. Myofibril ATPase activity of rat plantaris increased from the 10d to 12 week animals (P < 0.05). As anticipated, training resulted in a lowered activity at 6 and 12 weeks compared to controls.
• 5.5. The Ca²⁺ uptake and Ca²⁺-ATPase activity of the sarcoplasmic reticulum followed a similar pattern.
• 6.6. With regard to the exercise-rest rats, the myofibril and SR ATPase activities at 12 weeks were comparable to the 12 weeks control rats.
• 7.7. The rest-exercise group approximated the 12 week training group with regard to myofibril and SR ATPase activities (P > 0.05).
• 8.8. The results suggest that the training adaptations that occur during development of skeletal muscle return to normal, when training ceases in the adult rat.
• 9.9. Furthermore, animals that started to train prior to puberty do not have a greater capacity to adapt than animals which initiated training during adulthood.

     

Long-term starvation in Xenopus laevis daudin—III. Effects on enzymes in several tissues

• 1.1. Adult, female Xenopus laevis were subjected to 12 months of starvation.
• 2.2. Starvation resulted in a continuous reduction in the activity of both hepatic and renal glucose-6-phosphate dehydroganse.
• 3.3. Fructose-1,6-diphosphatase was significantly reduced at months 10 and 12 in the liver, and at months 4, 10, and 12 in the kidney.
• 4.4. Pyruvate kinase activity of muscle and liver decreased during the experimental period whereas the renal enzyme remained essentially unchanged.
• 5.5. Both hepatic and renal glutamate-pyruvate transaminase (GPT) and hepatic glutamate-oxaloacetate transaminase (GOT) showed a reduction of activity after 2 and 4 months of starvation followed by an increase in GPT but not in GOT.