Collagenolytic activity of a soil actinomycete

A soil actinomycete hydrolyzed collagen extracted from bovine Achilles tendon, calf skin, carp swim-bladder and rat tail tendon. Glucose, mannose, aspartic acid and asparagine increased its collagenolytic activity which was optimum at 28 °C and at pH 7.2 – 7.5. Metallic ions, NaEDTA, cysteine, 4-chloromercuribenzoate, glutathione and sodium azide were inhibitory.     

Dryinid parasitoids of rice leafhoppers and planthoppers in the Philippines II. Rearing techniques

Three new techniques of rearing dryinids parasitising rice hoppers were developed, namely, laboratory rearing technique for detailed observations, device for transporting and rearing field-collected hoppers to estimate percentage parasitism and a breeding technique.

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Résumé Trois nouvelles techniques d’élevage de dryiinides parasites des cicadelles du riz ont été mises au point. L’une pour l’élevage en laboratoire en vue d’observations précises, un système pour le transport et l’élevage de cicadelles récoltées dans la nature afin d’évaluer le pourcentage de parasitisme et une technique d’élevage permanent.

     

Increased production of cellulase of Trichoderma sp. by pH cycling and temperature profiling

Cultivation of Trichoderma reesei QM 9414 on 3% (w/v) cellulose medium (C/N ratio = 8.5) produced 4.5 IU/ml celulase 180 hr at a cell growth of 8.0 g/liter (0.266 g cell/g cellulose). It corresponded to an average cellulase productivity 25.0 IU/liter/hr (3.5 IU/g cell/hr). In the same medium 9.5 g/liter cell mass (0.316 g cell/g cellulose), 6.2 IU/ml cellulase, and 38.75 IU/liter/hr (4.0 IU/g cell/hr) cellulase productivity could be obtained using pH cycling condition during cultivation. Cell mass, cellulase yield, and productivity were further increased to 10.0 g/liter, 7.2 IU/ml, and 44.0 IU/liter/hr (4.5 IU/g cell/hr), respectively, by simultaneous pH cycling and temperature profiling strategy. Results are described.     

Morphology,serology and biochemical characters of phage CVX-5, isolated from a patient with colitis

Electronmicroscopic observations indicate that bacteriophage CVX-5 has an angular head with long spiral tail which is noncontractile, possibly having 2--3 tail fibres attached at the distal part of the tail. This phage is antigenically unrelated to any of the T-phages. Inhibition of phage CVX-5 multiplication by mitomycin C and incorporation of 3H-thymidine into this phage indicate that phage CVX-5 is a DNA phage.     

Studies on intestinal protease: Isolation,purification and effect of dietary proteins on alkaline protease activity of the air-breathing fish,Clarias batrachus (Linn.)

1. The effect of dietary protein levels on the proteolytic activity in the intestines of the air-breathing fish, Clarias batrachus (Linn.) has been studied
2. Activity of proteolytic enzymes increased significantly in fishes maintained with a 50% protein diet from those maintained with a 25% protein diet; still higher dietary protein percentage showed no further stimulation of enzyme activity.
3. In a study on the determination of sub-cellular localisation, it has been found that protease activity is more prominent in lysosomes than in other organelles of the cell.
4. A sixty fold purification of alkaline protease from the intestine of Clarias batrachus has been achieved by ion exchange chromatography on DEAE cellulose which has been further checked by polyacrylamide gel electrophoresis.

     

Protein kinases of the chick oviduct: a study of the cytoplasmic and nuclear enzymes.

Subcellular fractionation of oviduct tissue from estrogen-treated chicks indicated that the bulk of the protein kinase activity of this tissue is located in the cytoplasmic and nuclear fractions, DEAE-cellulose chromatography of cytosol revealed a major peak of cAMP stimulatable activity eluting at 0.2 M KCl. This peak was further characterized and found to exhibit properties consistent with cytoplasmic cAMP dependent protein kinases isolated from other tissues; it had a Km for ATP of 2 X 10(-5) M, preferred basic proteins such as histones, as substrate, and had a M of 165 000. Addition of 10(-6) M cAMP caused the holoenzyme to dissociate into cAMP binding regulatory subunit and a protein kinase catalytic subunit. Extraction of purified oviduct nuclei with 0.3 M KCl released greater than 80% of the kinase activity in this fraction. Upon elution from phospho-cellulose, the nuclear extract was resolved into two equal peaks of kinase activity (designated I and II). Peak I had a sedimentation coefficient of 3S and a Km for ATP of 13 muM. while peak II had a sedimentation coefficient of 6S and a Km for ATP of 9 muM. Both enzymes preferred alpha-casein as a substrate over phosvitin or whole histone, although they exhibited different salt-activity profiles. The cytoplasmic and nuclear enzymes were well separated on phospho-cellulose and this resin was used to quantitate the amount of cAMP dependent histone kinase activity in the nucleus and the amount of casein kinase activity in the cytosol. Protein kinase activity in nuclei from estrogen-stimulated chicks was found to be 40% greater than hormone-withdrawn animals. This increase in activity was not due to translocation of the cytoplasmic protein kinase in response to hormone, but to an increase in nuclear (casein) kinase activity. During the course of this work, we observed small but significant amounts of cAMP binding activity very tightly bound to the nuclear fraction. Solubilization of the binding activity by sonication in high salt allowed comparison studies to be performed which indicated that the nuclear binding protein is identical with the cytoplasmic cAMP binding regulatory subunit. The possible role of the nuclear binding activity is discussed.