Properties of protease inhibitors from the haemolymph of silkworms, Bombyx mori, Antheraea pernyi and Philosamia cynthia ricini

1. Effects of inhibitors in the haemolymph from three silkworms on proteases from the alimentary canal of respective insects were studied as well as those on bovine trypsin and alpha-chymotrypsin. 2. In Bombyx haemolymph, three inhibitor fractions were separated by gel filtration on Sephadex G-75. These fractions differed in the specificity of inhibition for different proteases and in thermal stability. 3. In Antheraea haemolymph, a relatively different elution profile was observed compared to that of Bombyx. Philosamia haemolymph showed the intermediate type of elution pattern. 4. Inhibitors from the haemolymph of Antheraea and Philosamia were heat stable. 5. Distinct electrophoretic patterns of inhibitors were observed in three silkworms.

Effects of starvation and infection with Schistosoma mansoni on the release rate of free amino acids (FAA) by Biomphalaria glabrata

1. The elimination of dissolved free amino acids (FAA) by individual snails during a period of 2 hr was measured. The FAA concentration in the hemolymph and in the homogenate also was determined. 2. For uninfected, normally fed snails a daily FAA production of 0.7 +/- 0.25 mumol glycine equivalents/g live wt was found. With snails starving for 7 days the daily FAA release rate fell to a mean value of 0.44 +/- 0.19 mumol glycine equivalents/g live wt. Infection with Schistosoma mansoni, however, induced higher FAA loss with an average of 1.72 +/- 1.07 mumol glycine equivalents/g live wt/day. 3. The FAA concentration in the homogenate of both starved and infected B. glabrata was significantly reduced by comparison to the levels found for normally fed snails. 4. A clear drop in FAA concentration was found in the hemolymph of starved and infected snails, respectively. 5. The FAA concentrations in the hemolymph and the homogenate of parasite-bearing snails does not differ significantly from the results found for starved snails. By contrast, the FAA release of infected B. glabrata significantly increased in comparison to that of the starved snails.

Identification of the HA-2 agglutinin in the haemolymph of the ascidian Botrylloides leachii as the factor promoting adhesion of sheep erythrocytes to mouse macrophages

The HA-2 agglutinin purified from B. leachii haemolymph is shown to mediate the binding of sheep erythrocytes to mouse macrophages. This agglutinin appears to be wholly responsible for the adhesive activity of haemolymph, since upon chromatography of the latter through Sephadex G-200, the adhesive activity for both sheep and guinea pig erythrocytes was confined to those fractions containing the HA-2 agglutinin. The HA-1 agglutinin recovered in earlier fractions was unable to promote the adhesion of guinea pig erythrocytes to macrophages. Adsorption experiments indicated that this was due to a lack of ligand sites on the macrophage surface. These data support earlier conclusions that the HA-1 and HA-2 agglutinins have distinct binding specificities.

Isolation and characterization of the haemolymph lipoproteins of Triatoma infestans

1. Three lipoproteins differing in hydrated densities were isolated by ultracentrifugal procedures from the haemolymph of adult and fasted Triatoma infestans. 2. They are the high density lipoprotein HDL (d = 1.115-1.152) and the two very high density lipoproteins VHDL-I (d = 1.190-1.231) and VHDL-II (d = 1.245-1.260). HDL was the predominant lipoprotein. 3. The total lipid content expressed as % of lipoprotein weight in HDL, VHDL-I an VHDL-II was 30.1, 7.8 ad 2.9% respectively. Diacylglycerols are the predominant lipids of HDL (38.7%) and VHDL-I (27.0%) but only amount of 6.2% in VHDL-II. 4. Triacylglycerols are minor components (about 6.0%) of all fractions. 5. The phospholipids (phosphatidylethanolamine and phosphatidylcholine), sterols, sterol esters and hydrocarbons were present in all lipoprotein fractions. 6. Phospholipids and hydrocarbons were the most abundant lipids of VHDL-II.

Interactions between sex-transformation mutants of Drosophila melanogaster. I. Hemolymph vitellogenins and gonad morphology

In Drosophila, vitellogenins (yolk protein precursors) are synthesized by the female fat body, secreted into the hemolymph and subsequently taken up by the developing oocytes. The male fat body, on the other hand, does not do this even when immature ovaries are transplanted into the body cavity and grow. Thus, the hemolymph vitellogenins serve as an easily detectable sexually dimorphic biochemical marker.--We have examined hemolymph vitellogenins by SDS polyacrylamide gel electrophoresis in flies carrying various sex-transformation mutants (dsx, tra, tra-2 and tra-2OTF) singly and in all possible combinations. Chromosomal females homozygous for tra or tra-2 have no detectable hemolymph vitellogenins, while those homozygous for tra-2OTF exhibit appreciable levels of these proteins. Flies homozygous for dsx, both X/X and X/Y, have hemolymph vitellogenins, although the amount is consistently smaller in the latter. Indeed, X/Y; dsx/dsx is the only genotype in which hemolymph vitellogenins are detected in the X/Y flies. A clear hierarchy of epistasis exists among these sex-transformation mutants when they are examined in various combinations: dsx greater than tra, tra-2 greater than tra-2OTF. Moreover, an interaction between tra-2OTF and tra was seen in these experiments: X/X; tra-2OTF/tra-2OTF flies show the presence of only a trace of hemolymph vitellogenins when they are made heterozygous for tra. These results, combined with observations on gonad morphology, are discussed with respect to the Baker and Ridge (1980) hypothesis of sex determination.

Studies on the degradation of fibrinogen by proteolytic enzymes from the larvae of Lanomia achelous (Cramer)

Fibrinogen degradation products formed by the action of purified haemolymph and saliva of a Saturnidae caterpillar of the Lonomia genus were studies by immunoelectrophoresis and polyacrylamide/SDS gel electrophoresis. The pattern of degradation differ form the one described for plasmin, trypsin, brinase, and ochrase. The most striking difference being the rapid loss of the alpha chain in spite of the presence of the protease inhibitor aprotinin, and/or denaturalizing agents such as 8 M Urea and 2% SDS.

Subunit heterogeneity of Cancer magister hemocyanin

Hemocyanin from the Dungeness crab, Cancer magister, has been described as a 25-S two-hexamer assembly of two different 5-S subunits. We have found that at least six different 5-S polypeptide chains constitute this hemocyanin. They can be separated from one another by sodium dodecyl sulfate slab gel electrophoresis as well as by regular gel electrophoresis. The six 5-S polypeptides appear very different from one another when each SDS-treated subunit is partially digested with Staphylococcus aureus V8 protease. This pattern of six subunits is present both in hemolymph which has been examined immediately upon removal from the animal as well as in hemocyanin which has remained at room temperature for two weeks. Thus, it is unlikely that the heterogeneity is a result of proteolysis during preparation of the sample. Possible implications of the high degree of subunit heterogeneity on the protein's quaternary structure are discussed.

Characterization and distribution of the hydrocarbons found in diapausing pupae tissues of the tobacco hornworm, Manduca sexta (L.)

The cuticular hydrocarbons of diapausing pupae of the tobacco hornworm, Manduca sexta (L.), are composed of two types of hydrocarbons: n-alkanes (3%) and unsaturated hydrocarbons (97%). The integument, fat body, muscle, and hemolymph are composed of three types of hydrocarbons: n-alkanes (9, 6, 9, and 2%, respectively), branched alkanes (75, 85, 80, and 56%, respectively), and unsaturated hydrocarbons (16, 9, 11, and 42%, respectively). The absence of branched alkanes on the cuticular surface indicated that hydrocarbons are selectively synthesized or deposited according to the presence or absence of methyl branches in the molecule. The hydrocarbons consisted of homologous series of n-alkanes from 21 to 41 carbon atoms, monomethylalkanes from 23 to 39 carbon atoms, dimethylalkanes from 25 to 43 carbon atoms, and trimethylalkanes from 33 to 37 carbon atoms. All branched components had methyl groups near the center of the molecule, and the di- and trimethyl branched components had three methylene units between the branch points. Straight chain alkenes, alkadienes, and alkatrienes from 23 to 44 carbon atoms were partially characterized. The percentage composition of each homologous series varied from tissue to tissue.

Diacylglycerol-carrying lipoprotein of hemolymph of the American cockroach: purification, characterization, and function

A diacylglycerol-carrying lipoprotein (DGLP) was isolated from the hemolymph of adult male and female American cockroaches, Periplaneta americana. The purification procedure involved dialysis against distilled water, precipitation at low ionic concentration at pH 6.6, and separation by column chromatography on DEAE-cellulose. The final preparation was homogeneous as judged by polyacrylamide gel electrophoresis and electron microscopy. The lipoprotein comprised over 50% of the total hemolymph protein. The DGLP molecule was almost globular in shape with a diameter of approximately 160 A. The molecular weight, determined by a sedimentation-equilibrium method, was approximately 600,000. Apoprotein of DGLP consisted of two subunits, heavy chain (mol wt 250,000) and light chain (mol wt 85,000). The total lipid content of DGLP amounted to about 50%. The lipids comprised diacylglycerol (15% of total lipid), hydrocarbons (28%), cholesterol (5%), and phospholipids (43%). n-Pentacosane, 3-methylpentacosane, and 6,9-heptacosadiene were identified as major hydrocarbons. Mannose(0.9%) and glucosamine (0.3%) were associated with apoprotein of DGLP. The capacity of the purified DGLP to accept diacylglycerol from both fat body and midgut was demonstrated in vitro; thus it was suggested that the same carrier molecule served to transport this lipid from storage site and absorption site. The possible multiple role of cockroach DGLP in transporting such lipids as diacylglycerol, cholesterol, and hydrocarbon from the site of storage, absorption, or synthesis is discussed.

[Scorpionidae of the great Arabic Maghreb. IV. Fractionation of venom from Androctonus mauretanicus (Pocock, 1902) of Morocco]

The author points out a simple chromatographic technic to fractionate venom of Androctonus mauretanicus (Pocock, 1902) from Morocco.

[Influence of the pars intercerebralis and of median sub-ocellar neurosecretory cells on the concentration of vasopressin-like substance in the ventral nerve cord and haemolymph of Locusta migratoria (Orthoptera). Radioimmunoassay and immunohistology (author's transl)]

1 degree In the migratory locust, electrocoagulation of the neurosecretory cells of the pars intercerebralis increases the rate of water elimination, while electrocoagulation of the median sub-ocellar neurosecretory cells elicits a marked water retention. 2 degrees In the first type of experiment, high concentrations of molecules antigenically close to vasopressin can be measured by RIA in the haemolymph; such molecules are practically undetectable in the blood when median sub-ocellar neurosecretory cells are suppressed. 3 degrees Our data lead us to assume that the vasopressin-like molecules detected in the migratory locust promote water elimination.

Comparison of the larval serum proteins of Drosophila melanogaster using one and two-dimensional peptide mapping

Immunological data, amino acid composition, and coordinate control during development suggest that the alpha, beta and gamma subunits of the major protein of Drosophila larval serum (LSP-1) are coded for by genes which evolved by replications of an ancestral gene followed by mutation. In order to test this hypothesis, and to study the relationship of these genes with that coding for the second major larval serum protein subunits. One-dimensional maps generated by three different proteases showed many similarities among these proteins. Two-dimensional peptide mapping of the methionine-containing tryptic peptides showed that half of these peptides are common to all four larval serum protein subunits, and that about two-thirds are common to the three LSP-1 subunits. These observations show that the LSP-1 subunits are more closely related to each other than any is to LSP-2, and supported the initial suggestion that the proteins are homologous. Because the genes for the LSP-1 subunits are each located on a different chromosome, the LSP-1 subunits are a suitable system for investigating the evolution and dispersal of related genes, and trans control in eukaryotes.

Chiral 1,2-diacylglycerols in the haemolymph of the locust, Locusta migratoria

A 1H-NMR method using chiral shift reagents was applied in the stereochemical analysis of the haemolymph 1,2-diacylglycerols of Locusta migratoria. Conversion of the 1,2-diacylglycerols into 1,2-diacetyl-3-tritylglycerols allowed the accurate determination of the enantiomeric purity, whereas direct trimethylsilylation of the unmodified or hydrogenated haemolymph 1,2-diacylglycerols proved to be less suitable because of signal broadening. In the haemolymph of Locusta, sn-1,2-diacylglycerols with a remarkably high optical purity were found to be present. In the resting locust, at least 96% of the haemolymph 1,2-diacylglycerols have the sn-1,2-configuration, in locusts in which the haemolymph diacylglycerol concentration was elevated by fat body triacylglycerol mobilization induced by flight activity or injection of adipokinetic hormone, over 97% of the 1,2-diacylglycerols is the sn-1,2-enantiomer. The few percent sn-2,3-enantiomer may not have been present initially. Positional distribution of the fatty acids in the fat body triacylglycerols and in the haemolymph sn-1,2-diacylglycerols obtained from locusts after a 2 h flight revealed nearly identical occupation of the sn-2-positions in both acylglycerols. The distribution patterns in the sn-1-position of the 1,2-diacylglycerols and the combined sn-1 and sn-3 positions of the triacylglycerols are compatible with the possible existence of a stereospecific sn-3-triacylglycerol lipase.

Leptinotarsin: a presynaptic neurotoxin that stimulates release of acetylcholine

Leptinotarsin, a toxin found in the hemolymph of the beetle Leptinotarsa haldemani, can stimulate release of acetylcholine from synaptic termini. Leptinotarsin causes an increase in the frequency of miniature end plate potentials (mepps) of the rat phrenic nerve-diaphragm preparation. The increase in the frequency of mepps induced by leptinotarsin is biphasic: about 10% of the total mepps are released in an initial burst that lasts about 90 sec, after which the remaining mepps are released over a period of 10-20 min. Tetrodotoxin has no effect upon the release induced by leptinotarsin, but low-Ca(2+) conditions abolish the first phase. The two phases of release may represent two presynaptic pools of acetylcholine, both of which can be released in quantized form. In a second study, rat brain synaptosomes were incubated with [(3)H]choline and were immobilized on Millipore filters. Leptinotarsin induced release of [(3)H]acetylcholine from this preparation, confirming the release seen by using neurophysiological methods. The ability of leptinotarsin to induce release from either intact nerve terminals or synaptosomes was abolished when the toxin was heated. The releasing activity of leptinotarsin from synaptosomes was also partially dependent upon the presence of Ca(2+) in the perfusing solution. Release from synaptosomes followed first-order kinetics, and was not inhibited by commercial antibodies to black widow spider antigens. The data suggest that leptinotarsin acts as a presynaptic neurotoxin and may be of value as a mechanistic probe in understanding the storage and release of neurotransmitters.

Haemolymph protein concentration of Scylla serrata : assessment of quantitative methods and intra-individual variability

The suitability of micro-Kjeldahl, biuret and Folin-Ciocalteu methods of protein determination in analysing the haemolymph protein concentration of Scylla serrata was assessed. It was found that biuret method is simple, reliable and the results are consistent. Intra-individual factor as a function of time of day is also responsible for individual variability in the haemolymph protein concentration of the crab.

Carbohydrate reserves and hemolymph sugars of the African giant snail, Achatina fulica in relation to parasitic infection and starvation

In the snail, Achatina fulica, parasitized by the rat lungworm Angiostrongylus cantonensis, levels of carbohydrate in hemolymph and digestive glands were determined. The normal level of hemolymph glucose of 11.7 mg% dropped to 4.25 mg% in the infected snails, a significant difference after only one week of infection. The level of total reducing sugar in the hemolymph also decreased significantly (12.3 mg% to 3.6 mg%) in this period. Later on, the snails were capable of adapting themselves to the parasitic infection and the concentration of hemolymph sugars returned to the normal range. Starvation caused a decrease in the carbohydrate reserves of the digestive gland only when the starved snails had been previously infected.