Crystallization and characterization of the recombinant human Clara cell 10-kDa protein

Crystals of recombinant human Clara cell 10-kDa protein were grown both from ammonium sulfate and polyethylene glycol (PEG) solutions. Crystals grown from ammonium sulfate solution have been characterized by X-ray diffraction studies as monoclinic with the space group C2 and lattice constants a = 69.2 Å, b = 83.0 Å, c = 58.3 Å, and β = 99.7°. The monoclinic crystals diffract to beyond 2.5 Å. Some of the crystals grown from PEG were of a similar habit to those grown from ammonium sulfate, but others were triclinic with the space group P1 and cell constants a = 40.3 Å, b = 46.3 Å, c = 51.3 Å, α = 117.7°, β = 102.3°, and γ = 71.4°. These crystals diffract to beyond 3.2 Å. © 1994 Wiley-Liss, Inc.     

New biologically active epidioxysterols from Stereum hirsutum

From the fungus Stereum hirsutum have been isolated and identified two new epidioxysterols 1, 4, together with two known ones 2 and 3. Their structures were elucidated on the basis of spectroscopic analysis and chemical reactions. Epidioxysterols 1-4 have been shown to possess a significant activity against Mycobacterium tuberculosis.     

SITE OF BIOSYNTHESIS OF BRAIN-SPECIFIC PROTEINS IN THE GIANT FIBRE SYSTEM OF THE SQUID

The synthesis of brain-specific proteins has been examined in perikaryal and axonal regions of the giant fibre system of the squid. After in vitro incubation of stellate ganglia, stellate nerves and isolated giant axons with radioactive amino acids, the labelled soluble proteins have been extracted from the giant fibre lobe, the axoplasm and the axonal sheath of the giant axon and have been separated by gel electrophoresis on a continuous system. In addition, they have been challenged with antisera prepared against the cephalopod brain-specific proteins L1 and L2 and the resulting precipitate has been resolved by sodium dodecyl sulphate-gel electrophoresis. Synthesis of these two proteins appears to be restricted to the giant fibre lobe, while an additional discrete protein band (L5) also becomes clearly labelled in the isolated giant axon. Radioactive components migrating in the region of the L1 and L2 proteins are synthesized in the isolated giant axon. They can be distinguished from tbese proteins on the basis of electrophoretic and immunochemical criteria.     

DNA POLYMERASE ACTIVITY FROM THE BRAIN OF OCTOPUS VULGARIS LAM

Abstract— The DNA polymerase of the optic lobes of Octopus vulgaris Lam has been solubilized and some of its properties have been investigated. The enzyme catalyses the incorporation of [³H]thymidine triphosphate into a DNase-sensitive, acid-insoluble product in the presence of DNA, the four deoxynucleoside triphosphates and Mg²⁺. The pH optimum is between pH 9.2 and 9.6, the optimal concentration of Mg²⁺ is between 10 and 30 mM and the optimal temperature is in the range 27°-30°C. The content of enzyme per mg protein is highest in the vertical and optic lobes and lowest in the suboesophageal lobe.     

Deprivation of paradoxical sleep effect on weight and nucleic acid content of liver and brain

Male Wistar rats weighing between 200 and 350 g were deprived of paradoxical sleep (PS-D) by placing them on small platforms surrounded by water. In comparison with rats kept in similar cages but without water, PS-D animals manifested a marked decrease in body and liver weight, which depended on animal size and on time of exposure to the condition of PS-D. A comparable weight loss occurred in the spleen, while more limited effects were present in brain and cerebellum. Exposure to the condition of PS-D induced a pronounced increase in the concentration of liver DNA and RNA. The latter effect occurred considerably earlier. On the other hand, only limited and uncertain variations were noted in the DNA concentration of brain and cerebellum. Body and liver changes were readily reversed after a period of recovery lasting two days.     

IDENTIFICATION OF A GROUP OF OCTOPUS BRAIN PROTEINS AS HISTONES

Abstract— We have investigated the subcellular localization of a group of proteins solubilized with SDS from saline-washed particulates of octopus brain and identified as the most rapidly moving species in SDS-gel electrophoresis. These proteins are several-fold more concentrated in the vertical and optic lobes than in the suboesophageal lobe. In the optic lobe their concentration decreases with increasing body weight (G iuditta et al , 1975).
Upon separation of hypertonic sucrose homogenates from the optic lobe in a nuclear pellet and in a floating layer containing cytoplasmic particulates, the proteins appear associated with the nuclear fraction. Differential extraction of the latter fraction shows that the proteins have the same solubility and electrophoretic mobilities as histones. Proteins with similar properties are present in other brain regions and in non-nervous organs.