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.

     

Hydrolysis of glycol chitin by chitinolytic enzymes

• 1.1. The hydrolysis of glycol chitin preparations by several β-N-acetylglucosaminidases was monitored colorimetrically with the potassium ferriferrocyanide reagent.
• 2.2. Glycol chitin samples from crab and insect sources varied considerably in chemical composition and susceptibility to enzymatic hydrolysis.
• 3.3. Insect endochitinase preferred crab glycol chitin as substrate while hen's egg white lysozyme preferred commercial glycol chitin.
• 4.4. Insect glycol chitin was well hydrolyzed by both enzymes.
• 5.5. Insect exochitinase did not digest glycol chitin.

     

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.

     

Osmoregulatory adjustments by three atherinids (Leptatherina presbyteroides; Craterocephalus mugiloides; Leptatherina wallacei) to a range of salinities

• 1.1. Patterns of osmoregulation were studied in three species of Swan river atherinids (Leptatherina presbyteroides, lower estuarine and marine; Craterocephalus mugiloides, mid estuarine; Leptatherina wallacei, upper estuarine) over a wide range of salinities.
• 2.2. The plasma Na⁺ concentration was elevated with an increase in salinity.
• 3.3. Haematocrit and body water content decreased with acclimation to higher salinity.
• 4.4. All three species of atherinids osmotically regulated over a salinity range greater than that which these fish are reported to occur in.

     

IDentification of a microsomal retinoic acid synthase as a microsomal cytochrome P-450-linked monooxygenase system

• 1.1. To characterize an enzyme which metabolizes retinal in liver microsomes, several properties of the enzymatic reaction from retinal to retinoic acid were investigated using rabbit liver microsomes.
• 2.2. The maximum pH of the reaction in the liver microsomes was 7.6.
• 3.3. The K_m and V_max values for all-trans, 9-cis and 13-cis-retinals were determined.
• 4.4. The reaction proceeded in the presence of NADPH and molecular oxygen.
• 5.5. The incorporation of one atom of molecular oxygen into retinal was confirmed by using oxygen-18, showing that the reaction comprised monooxygenation, not dehydrogenation.
• 6.6. The monooxygenase activity was inhibited by carbon monoxide, phenylisocyanide and antiNADPH-cytochrome P-450 reductase IgG, but not by anti-cytochrome b₅ IgG.
• 7.7. The enzymatic activity inhibited by carbon monoxide was photoreversibly restored by light of a wavelength of around 450 nm.
• 8.8. The retinal-induced spectra of liver microsomes with three isomeric retinals were type I spectra.
• 9.9. The microsomal monooxygenase activity induced by phenobarbital or ethanol were more effective than that by 3-methylcholanthrene, clotrimazole or β-naphthoflavone.
• 10.10. These results showed that the monooxygenase reaction from retinal to retinoic acid in liver microsomes is catalyzed by a cytochrome P-450-linked monooxygenase system.

     

The effect of myo-inositol on the ability of Ditylenchus dipsaci,D. myceliophagus and Anguina tritici to survive desiccation

• 1.1. The effect of myo-inositol on the ability of three species of nematodes to survive desiccation has been studied.
• 2.2. Survival rates obtained from worms treated with an inositol bathing medium were compared with survival rates of worms treated with distilled or tapwater media.
• 3.3. Highest survival rates were found in those nematodes that were placed in an inositol solution prior to desiccation.
• 4.4. Tapwater facilitated higher revival rates than did distilled water in both D. dipsaci and D. myceliophagous.
• 5.5. No such differences were found for A. tritici.
• 6.6. The results are discussed in relation to the possible mechanisms of protection afforded by the different bathing media.

     

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.

     

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.

     

Chemical cross-links of proteins by using bifunctional reagents

• 1.1. The chemical identification of spatial arrangements of the subunits in oligomeric proteins is exclusively achieved by the analysis of the reaction products of the protein and bifunctional reagents.
• 2.2. Since the pioneer work of Hartman and Wold (Biochemistry6, 2439–2448, 1967) the bifunctional reagent such as bis-imido-esters was first introduced into protein chemistry.
• 3.3. We have listed the non-cleavable and cleavable bis-imido-esters, the N-hydroxy-succinimido-csters and the aryl azides which once photolyzed, become the highly reactive nitrene intermediates.
• 4.4. Different reagents classified as homo- and hetero-bifunctional reagents are also listed.
• 5.5. The advantages and limits of each group as well as their chemical properties are advanced and extensively discussed.

     

Electrophoretic identification of bird species involved in collisions with aircraft

• 1.1. The utility of biochemical genetic methods of bird identification was investigated for some common species which create a hazard for commercial aviation in Ireland.
• 2.2. Sixteen enzyme loci were assayed in eight species, using starch gel electrophoresis; three larids, three corvids and two columbids.
• 3.3. Genera were distinguishable using all but two loci.
• 4.4. Differences within genera were small, but all species except for the gulls Larus argentatus and L. marinus, could be identified using one or more loci.
• 5.5. Arising from the success of the method using fresh specimens, a protocol for the electrophoretic identification of traumatized remains of strikes is suggested.

     

Purification and characterization of hatching enzyme of the pike (Esox lucius)

• 1.1. A choriolytic enzyme was isolated from the hatching medium of the pike, Esox lucius.
• 2.2. The enzyme is defined as hatching enzyme.
• 3.3. The molecular weight of the enzyme is 24,000.
• 4.4. The enzyme is a glycoprotein containing 2% carbohydrate.
• 5.5. Its isoelectric point is 6.5.
• 6.6. The pH optimum is around pH 8.
• 7.7. The enzyme molecule contains two disulfide bonds but no free cysteine.
• 8.8. Inhibitor studies and metal analysis show that the enzyme is a zinc-metalloprotease.

     

Modulation of active potassium transport by aldosterone

• 1.1. The role of aldosterone on active potassium transport across lizard colon under voltage-clamped conditions has been investigated.
• 2.2. Control colons exhibited no net potassium flux (J^k_net) despite of the existence of active opposite unidi ectional fluxes.
• 3.3. An important net secretory potassium flux was found in short-circuited aldosterone-stimulated colons.
• 4.4. Mucosal amiloride did not change (J^k_net) either in control or aldosterone-stimulated colons.
• 5.5. Luminal barium alters K ⁺ transport in a manner consistent with the presence of barium-sensitive conductances at the apical membrane of both control and aldosterone-treated colons.
• 6.6. The effects of ouabain and barium on control and aldosterone-induced potassium flows were consistent with a model involving basolateral uptake by an Na ⁺-K ⁺-ATPase and conductive exit across the apical membrane.
• 7.7. The stimulatory effect of aldosterone on potassium secretion is associated with parallel increases of both basolateral K ⁺ entry and the apical conductive pathway.

     

Liver glycogen mobilization by Trypanosoma brucei sonicates

• 1.1. The African trypanosome, T. brucei, appears to possess a hormone-like substance capable of stimulating the production of glucose from glycogen.
• 2.2. The effect of this substance is primarily on the liver as demonstrated in vitro.
• 3.3. The effect is consistent and independent of host conditions provoking an immune response.
• 4.4. The data are discussed with respect to the endocrinological aspects of the host and its corresponding involvement.

     

2-Deoxyglucose transport by the frog sartorius: Effects of electrical stimulation and N-carbobenzoxy-glycyl-l-phenylalaninamide

• 1.1. Studies characterizing glucose transport in the frog sartorius were performed.
• 2.2. For nonstimulated and stimulated muscles, intracellular 2-deoxyglucose exceeded 2-deoxyglucose-6-phosphate at 15 min, showed little further increase, and was maintained below the extracellular concentration for 2 hr.
• 3.3. Accumulated 2-deoxyglucose-6-phosphate did not inhibit glucose transport.
• 4.4. Unlike in adipocytes, basal and stimulated 2-deoxyglucose transport showed no difference in sensitivity to N-carbobenzoxy-glycyl-l-phenylalaninamide.
• 5.5. Phenylarsine oxide blocked contraction-enhanced 2-deoxyglucose uptake.
• 6.6. These results suggest that the glucose transporter of the sartorius exhibits auto-regulation, and that basal transport is not regulated by the same process as in adipocytes.

     

Induction of autoantibodies against spermatozoa by injection of allogeneic sperm in the Nile Tilapia,Oreochromis niloticus

• 1.1. The sperm-agglutinating factor (SAF) could be induced in the serum of male Nile tilapias, Oreochromis niloticus, by injection of allogeneic sperm.
• 2.2. Only one class of molecules was demonstrated to be SAF in the serum.
• 3.3. Analysis on purified SAF revealed it to be a tetrameric molecule of IgM with a mol. wt of 760kD.
• 4.4. Cross reaction of the IgM with sperm of other teleost species suggests that sperm-specific surface antigens may be in evolution.

     

The binding and degradation of 125I-labelled insulin by rat kidney brush-border membranes

• 1.1. The interaction of insulin with purified brush-border membranes from rat kidney was studied with the use of [¹²⁵I]insulin.
• 2.2. The specific binding of insulin by brush-borders could be demonstrated, and was time- and temperature-dependent.
• 3.3. [¹²⁵I]insulin was displaced by unlabelled insulin. A₁-B₂₉ dodecoyl insulin and insulin A- and B-chains in proportion to their relative bioactivity.
• 4.4. Brush-border membranes showed high insulin-degrading activity with an apparent K_m of 2.2 μM.
• 5.5. A number of proteinase inhibitors were effective in inhibiting insulin degradation but the greatest degree of inhibition was achieved by the use of thiol-blocking reagents.
• 6.6. No evidence was obtained for the involvement of the enzyme glutathione-insulin transhydrogenase.

     

Sterol composition of three marine sponge species from the genus Cinachyrella

• 1.1. The hitherto undescribed sterol compositions of three marine sponge species belonging to the genus Cinachyrella are reported: C. alloclada and C. kükenthali from the Senegalese coast, at two different depths, and C. aff. schulzei from the lagoon of Nouméa, New Caledonia.
• 2.2. Fourteen free sterols have been identified by GC and GC/MS studies, including the 23,24ξ-dimethylcholesta-5,22-dien-3β-ol (10) and the rare 24-norcholesta-5,22-dien-3β-ol (1).
• 3.3. The first compound (10) is reported for the second time in a marine sponge and it was found only in Senegalese sponges collected in shallow waters.
• 4.4. Sterol (10) has been isolated by HPLC and identified by NMR techniques.
• 5.5. Significant amounts of cholest-7-en-3β-ol (7) were also found in the Senegalese sponge species.
• 6.6. Apart from these two compounds, the three sponge sterol compositions are found to be very similar.

     

Characteristics of Crassostrea virginica crystalline style chitin digestion

• 1.1. Fundamental chitin digestion characteristics of Crassostrea virginica crystalline style were investigated.
• 2.2. Optimum temperature and pH were 34°C and 4.8. respectively.
• 3.3. The colloidal regenerated chitin (0.56mol/0.5 ml: GlcNAc equivalents) was saturating under all enzyme levels encountered.
• 4.4. There was no evidence of end product inhibition, even after 100 hr incubation.
• 5.5. Calculated K_m for the chitinase complex was 1.19mM when determined using a 30 min assay, but was only 0.70 mM when determined using a 4.6 hr assay.
• 6.6. Both K_m values are lower than reported for similar assays in other molluscs and for most bacteria.
• 7.7. Effect of substrate preparation on the kinetics are discussed.
• 8.8. Eight peaks of chitinase activity were resolved by DEAE-Fractogel ion exchange chromatography.

     

Effect of lindane on phosphatidylinositol synthesis by cerebral cortex after acute and subchronic treatment

• 1.1. The incorporation of myo-[2-³H]inositol into phosphatidylinositols was unmodified in brain cortex miniprisms from convulsant rats.
• 2.2. However, the incorporation had increased by 300–400% in non convulsant rats which had received the same amount of lindane at a lower concentration.
• 3.3. This result suggests that phosphatidylinositols are implicated in the convulsion syndrome.
• 4.4. Experiments with lindane added in vitro were performed with both subchronically lindane intoxicated and untreated rats.
• 5.5. The results show an interesting lack of parallelism.
• 6.6. This might indicate the development of some resistance to the effects of lindane, possibly as the result of complex compensatory changes in inositol lipid biosynthesis.