A hemolytic protein secreted from epidermal cells of the Arabian Gulf catfish, Arius thalassinus (Ruppell)

1. A fright or shock induced toxic secretion (gel) from the epidermis of the Arabian Gulf catfish, Arius thalassinus, exhibits hemolytic activity when tested against red blood cells from many different sources. 2. An enzyme with hemolytic activity, which represents 1.1% of the total soluble gel protein fraction, has been purified to homogeneity. 3. Molecular sieve chromatography and SDS polyacrylamide gel electrophoresis of the purified protein indicate a mol. wt of 34,000. 4. One additional protein component with hemolytic activity was found in the epidermal secretion. 5. Specific activity of the catfish epidermal factor is 20.6 units/mg protein, a level somewhat lower than those of most protein hemolytic factors. 6. The catfish hemolytic factor was not ichthyotoxic when tested against small fish and did not cause lethality when administered intravenously to rabbits.     

A study on phosphoglucose isomerase enzyme in some elasmobranch fishes collected from Khor Al-Zubair, north west of the Arabian Gulf, Iraq

Tissue extracts of skeletal muscle, brain, gills, liver, kidney, heart, eye and spleen were electrophoretically examined for phosphoglucose isomerase (EC 5.3.1.9) activity in five species of elasmobranch fishes. Two phosphoglucose isomerases (PGI) with different specification have been found in all groups of elasmobranch fishes studied. PGI proved to be a good taxonomic criterion to differentiate members of the families Sphyrindae and Dasyatidae from the other remaining elasmobranch families. PGI appears to be controlled by duplicated genes as in other teleostean fishes.     

Protein composition of the threat induced epidermal secretion from the Arabian Gulf catfish, Arius thalassinus (Ruppell)

1. When threatened or injured, the Arabian Gulf catfish (Arius thalassinus, Ruppell) secretes a thick gel-like layer of proteinaceous material to its skin surface mainly from unicellular glands of the epidermis termed club cells. 2. Since a preparation from this secretion has been implicated in stimulation of the rate of wound healing in man and other test animals, the total gel protein composition was analysed by chemical, chromatographic and electrophoretic techniques. 3. Gel proteins were separated into soluble and insoluble fractions by extractions with increasingly strong solubilizing agents and the most insoluble components were solubilized only upon treatment with 10% SDS or concentrated organic acids. 4. Some of the soluble proteins from the secretion are also present in the insoluble protein fractions, indicating that the insoluble material is formed in part by aggregation of the soluble proteins. 5. The secretion was shown to be distinct from the catfish venom and differed greatly from typical fish mucus secretions in its composition and distribution of protein components.     

In vivo bioluminescence: A cellular reporter for research and industry

The detection of specific bacterial pathogens, indicator microorganisms and antimicrobial substances, and the recovery of microorganisms from sub-lethal injury, are all aspects of importance to industry which are currently being targeted using in vivo bioluminescence. In all instances, a key requirement for the application of bioluminescence is the establishment of a strict correlation between in vivo bioluminescence and cell viability, as determined by colony counting on agar plates. Comparative studies for biocides (phenol, chlorhexidine diacetate, phenol thioether), for a virucide (hypochlorite) and for cellular recovery of S. typhimurium from sub-lethal injury, all indicate that such a correlation is valid. Furthermore, real-time measurements of in vivo bioluminescence reveal a major population of bacterial cells that retain functional intracellular biochemistry, but are defective in their ability to replicate post of freeze injury.