Gary E. Rodrick

Release of lysozyme from hemolymph cells of Mercenaria mercenaria during phagocytosis

Activity of the lysosomal enzyme, lysozyme, has been quantitatively determined in the serum and cells of the hemolymph of Mercenaria mercenaria which had been exposed to known quantities of Bacillus megaterium and also in the serum and cells of hemolymph which had not been exposed to bacteria. The results indicate that the level of enzyme activity is greater in serum of hemolymph that had been exposed to B. megaterium and concurrently, there is an equivalent decrease in the level of activity in the cells. This evidence indicates that the amount of lysozyme released from cells into serum is enhanced during phagocytosis of the bacteria. n nIt has also been demonstrated that the release of lysozyme from cells occurs during the process of phagocytosis and is not a delayed phenomenon. n nEnzyme release by secondary phagosomes is reflected morphologically by what is commonly referred to as degranulation. This process does not involve the rupture of the plasma membrane of the hemolymph cells since biochemical studies have revealed that there is no release of the cytoplasmic enzyme, lactate dehydrogenase.

IDENTIFICATION AND CHARACTERIZATION OF LYSOZYME FROM THE HEMOLYMPH OF THE SOFT-SHELLED CLAM, MYA ARENARIA

Lysozyme activity has been demonstrated in the hemolymph of the soft-shelled clam, Mya arenaria. When whole hemolymph is centrifuged at 4000 and 10,000 x g and each constituent is assayed, lysozyme activity is found to be greater in the two supernatants than in the corresponding pellets.The lysozyme from M. arenaria hemolymph is salt dependent, relatively heat stabile, very sensitive to alterations in ionic concentration and the presence of heavy metals, and has an optimal pH of 5.0 when 0.1 M glycylglycine, 0.1 M imidazole, or 0.1 M phosphate buffers are employed but an optimal pH of 4.5 when 0.1 M Tris-HCl buffer is used.A Hill plot of the data resulting from salt reactivation studies indicates that the lysozyme in M. arenaria hemolymph includes at least 2.0 interacting binding sites for NaCl and KCl.When tested against a number of bacteria, the lysozyme is most active against Micrococcus lysodeitikus and Bacillus megaterium. It is less active against Proteus vulgaris, Salmonella pullorum, Shigella sonn...

Lysosomal and other enzymes in the hemolymph of Crassostrea virginica and Mercenaria mercenaria

Abstract 1. 1. The activities of lysozyme, acid and alkaline phosphatases, β-glucuronidase, amylase, lipase, glutamic-oxalacetic transaminase, and glutamic-pyruvic transaminase in the whole hemolymph and 4000 g pellets and supernatants of Crassostrea virginica and Mercenaria mercenaria were assayed. All of these enzymes, except for amylase, occurred in whole hemolymph as well as in the fractions of both species of molluscs. 2. 2. Amylase only occurred in the whole hemolymph and serum of C. virginica. Since this mollusc possesses a crystalline style, the amylase is believed to have originated from this structure. 3. 3. It is postulated that the lysosomal enzymes detected in the serum of both species of molluscs had been released from certain hemolymph cells and may play a role in destroying certain invading organisms.

Kinetic properties of lysozyme from the hemolymph of Crassostrea virginica

Abstract Lysozyme activity has been demonstrated in both the supernatant and pellet fractions of whole hemolymph of the American oyster, Crassostrea virginica , subjected to centrifugation at 4000 and 10,000 × g . In each case the enzyme activity is greater in the supernatant than in the pellet. The lytic activity of the molluscan lysozyme on Micrococcus lysodeikticus , like that of egg-white lysozyme, is salt dependent, is relatively heat stable, and is very sensitive to changes in ionic concentration. The optimal p H of the molluscan enzyme, however, ranges from 5.0 to 5.5, depending on the buffer employed. When tested against a number of bacteria, the oyster lysozyme has been found to be active against not only M. lysodeikticus but also Bacillus subtilis, B. megaterium, Escherichia coli, Gaffkya tetragena, Salmonella pullorum , and Shigella sonnei , although it is less active against the last four mentioned. It is not active against Staphylococcus aureus . It is postulated that the lysozyme in the serum of C. virginica has its origin in cytoplasmic phagosomes of granulocytes and is released when these organelles become ruptured.

A transmission and scanning electron microscopical study of the rectal ridge of Biomphalaria glabrata (Mollusca: Pulmonata)

SummaryThe rectal ridge of Biomphalaria glabrata is covered by a single layer of epithelium which includes cells with microvilli, ciliated cells, and goblet cells. Based on their ultrastructure, it is postulated that the cells bearing microvilli are involved in the transport of materials into and out of the organism. The underlying loose vascular connective tissue contains, among other components, large pigment cells which contain microtubule-like structures within cisternae of granular endoplasmic reticulum. These microtubule-like structures occur in either a dispersed or a condensed configuration. The two configurations may represent different stages of protein synthesis or they may be entirely different organelles.

An ontogenetic study of lactate dehydrogenase in Porocephalus crotali (Pentastomida)

Abstract 1. 1. The ontogenetic study of lactate dehydrogenase from Porocephalus crotali was undertaken using specific activities, optimal pH values, isoelectric points, Michaelis-Menten constants for lactate and nicotinamide adenine dinucleotide (NAD) and polyacrylamide-gel electrophoresis. 2. 2. Large changes in specific activities were noted, ranging from 3·6 in the infective egg to 13·5 in the infective nymph and 12·8 in the adult. 3. 3. Optimal pH ranged from 7·9 to 8·1 and small changes in K m s for lactate and NAD in all three developmental stages were observed. 4. 4. Anodal polyacrylamide-gel electrophoresis of Porocephalus crotali eggs, larvae, and adults has shown lactate dehydrogenase to consist of one, five, and five isoenzymes, respectively. 5. 5. LDH-4 is the predominant fraction in the nymphal and adult stages. 6. 6. In terms of electrophoretic mobility, LDH-1 of eggs corresponds to LDH-1 in the nymph and adult stages. 7. 7. Dramatic differences were found when the protein and lipoprotein patterns of the eggs, nymphs and adults were compared. 8. 8. These differences were in the electrophoretic mobility, number and density of the protein and lipoprotein fractions. 9. 9. Isoelectric focusing demonstrated five molecular forms of LDH from the nymph and adult stages while only one was found for the egg.