11-Trans leukotriene C: A naturally occurring slow reacting substance

A slow reacting substance, produced by murine mastocytoma cells, has been shown to have the structure 5(S)-hydroxy-6(R)-$\text{S}$-glutathionyl-7,9,11-$\text{trans}\text{-14-}\text{cis}\text{-eicosatetraenoic acid (11-}\text{trans}$ leukotriene C, previously referred to as leukotriene C-2) by ultraviolet spectroscopy, amino acid analyses, lipoxygenase conversion and comparisions with a synthetic compound of known structure and stereochemistry.     

Purification, characterization, and amino acid sequences of pepsinogens and pepsins from the esophageal mucosa of bullfrog (Rana catesbeiana)

Two pepsinogens (pepsinogens 1 and 2) were purified from the esophageal mucosa of the bullfrog (Rana catesbeiana), and their molecular weights were determined to be 40,100 and 39,200, respectively, by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The NH2-terminal 70-residue sequences of both pepsinogens are the same, including the 36-residue activation segment. Furthermore, a cDNA clone encoding frog pepsinogen was obtained and sequenced, which permitted deduction of the complete amino acid sequence (368 residues) of one of the pepsinogen isozymogens. The calculated molecular weight of the protein (40,034) coincided well with the values obtained by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. These results are incompatible with the previous report (Shugerman R. P., Hirschowitz, B. I., Bhown, A. S., Schrohenloher, R. E., and Spenney, J. G. (1982) J. Biol. Chem. 257, 795-798) that the major pepsinogen isolated from the bullfrog esophageal gland is a unique "mini" pepsinogen with a molecular weight of approximately 32,000-34,000. The two pepsinogens were immunologically indistinguishable from each other and related to human pepsinogen C. The deduced amino acid sequence was also more homologous with those of pepsinogens C than those of pepsinogens A and prochymosin. These results indicate that the frog pepsinogens belong to the pepsinogen C group. They were both glycoproteins, and therefore, this is the first finding of carbohydrate-containing pepsinogens C. Both pepsinogens were activated to pepsins in the same manner by an apparent one-step mechanism. The resulting pepsins were enzymatically indistinguishable from each other, and their properties resembled those of tuna pepsins.     

Isolation and identification of bile salts conjugated with cysteinolic acid from bile of the red seabream, Pagrosomus major.

Bile salts present in gallbladder of wild and cultured red seabream, Pagrosomus major, a marine teleost were analyzed. The bile from wild red seabream was found to contain two previously unknown bile salts along with two known bile salts, taurocholate and taurochenodeoxycholate. Isolation of each bile salt was performed by column chromatography. Fast atom bombardment mass spectra of the unknown bile salts showed the molecular ions (M-H)- of m/z 544 and 528 which are shifted 30 mass units upfield compared to those (m/z 514 and 498) of taurocholate and taurochendeoxycholate, respectively; this is consistent with the presence of cysteinolic acid (mol wt 155) instead of taurine (mol wt 125). Enzymatic hydrolysis of the bile salts released cholic acid and chenodeoxycholic acid, respectively, and an amino acid that was identified as D-cysteinolic acid by direct comparison with an authentic sample. From these results, the bile salts in the bile of wild red seabream were identified as the conjugates of cholic acid and chenodeoxycholic acid with cysteinolic acid. 1H- and 13C-magnetic resonance spectra of the bile salts were also consistent with the proposed structure. The cysteinolic acid conjugates were found only in wild and not in cultured red seabream; this distinction seems to result from differences in dietary cysteinolic acid.     

Microscopic observations of skin and lymphoid organs in the hairless dog derived from the Mexican hairless

The skin and lymphoid organs of Mexican hairless dogs and their hairless offspring were examined histologically. The hairless dogs lacked most hairs except for sparse hairs on the head, tail and feet. The skin of newborn pups consisted of a thick epidermis with epidermal ingrowths forming the rudiments of hair follicles. In older dogs more than 2 months of age, however, the epidermis was thin and the ingrowths were few. Neither hair follicles nor skin glands were present. The hairy skin of the head and tail had hair follicles with sebaceous glands. Regarding the lymphoid organs, the newborn pups possessed a thymus like haired pups. But in the older dogs more than 2 months of age, the thymus was atrophied and the lymphocyte population was too sparse to demarcate the cortex and the medulla. Lymphocyte accumulation in older dogs was also poor in the spleen and mesenteric lymph nodes. The present findings indicate that the hairlessness of the Mexican hairless dogs and their descendants is accompanied by early atrophy of the thymus after birth, and is followed by poor accumulation of lymphocytes in the thymus-dependent area of the spleen and the mesenteric lymph nodes. The defect of the thymus in the hairless dog seems to be different from that in athymic nude mice and rats. Further studies are needed to elucidate the immunological response and function in hairless dogs.     

Subcortical Rotation and Specification of the Dorsoventral Axis in Newt Eggs

The specification of the dorsoventral axis in naturally polyspermic eggs of the Japanese newt, Cynops pyrrhogaster , was first examined by studies on the spatial relationship between the dorsal midline of the future body plan and the sperm entrance points (SEPs ¹ ). On local insemination, the dorsal blastopore lip was usually found to be formed opposite the SEPs, as in anuran monospermic eggs. Next the movements of the subcortical layer and the cortex were analyzed. "Subcortical rotation" was observed, similar to that of Xenopus laevis eggs with respect to its timing and extent, and its direction was shown to predict the embryonic axis of the eggs. Thus, the dorsoventral axis was concluded to be determined by essentially the same mechanism in the newt as in Xenopus .
Owing to their large size and long first cell cycle, newt eggs appear to be suitable material for study of subcortical rotation, but their behavior is unique in that subcortical rotation occurs in only the vegetal hemisphere so that the subcortical layer stretches in the future dorsal side. Studies on the movement of Nile blue spots suggested that the cytoplasm under the cortex in newt eggs consists of two layers.     

Lipids and fatty acids of Leptospira interrogans serovar copenhageni virulent strain Shibaura.

Lipids and fatty acids of Leptospira interrogans serovar copenhageni virulent strain Shibaura were analyzed by thin-layer chromatography, gas-liquid chromatography, gas-mass spectrometry and infrared absorption spectrometry. The virulent cells possessed a characteristic lipid pattern consisting of free fatty acid (FFA) (41.8%), one major unidentified phospholipid (14.8%), phosphatidylethanolamine (PE) (12.9%), cholesteryl ester (CE) (9.3%), lysophosphatidylethanolamine (LPE) (4.9%) and diphosphatidyl-glycerol (DPG) (1.1%). Various fatty acids such as hexadecanoic (26.9%), hexadecenoic (15.4%), octadecenoic (26.5%) and octadecadienoic (27.4%) acids were detected in the FFA. The fatty acid composition of the major unidentified phospholipid distinctly differed from those of other lipids including PE, LPE, DPG and CE, and comprised mainly tetradecadienoic (53.6%), tetradecatrienoic (14.0%) and octadecanoic (13.8%) acids. This phospholipid with a large amount of polyunsaturated fatty acids with chain lengths of 14 carbon atoms was detected only in the lipids of the virulent cells.     

Dynamic sweating response of man to infrared irradiation in various spectral regions

In an attempt to detect differences in the thermal effect of infrared irradiation of different wavelengths, transient sweating response to infrared irradiation in various spectral regions was examined. In Series 1, the ventral or dorsal surface of the nude subject was irradiated repetitively for a period of 4 min (2 min on, 2 min off) by each of three kinds of infrared heaters with main emissivity in near-infrared (NIR; 0.7–2.8 m), intermediate-infrared (MIR; 1.5–5.8 m), and far-infrared (FIR; 2.8–25 m) regions. The sweating response on a non-irradiated area tended to be the greatest with MIR, while the magnitude of the sweating response on the irradiated area showed no consistent differences among various wavelengths. The results infer that MIR stimulated cutaneous thomoreceptors most effectively, while its direct effect on local sweat gland activity was minimal. In Series 2, the effects of 9–12 min irradiations in more restricted ranges of wavelength were compared by the combination of the three kinds of heaters with filters (translucent to wavelength ranges of 1.3–2.7, 2.7–3.5, 3.6–8.0 m, respectively). The sweating response on a remote area was predominantly greater with the range of 2.7–3.5 m than with the other wavelength ranges, while the local effect on sweating was minimal with this range. The results of Series 2 reinforce those of Series 1, indicating that the degree of stimulation of cutaneous thermoreceptors and of direct thermal effect on sweat gland activity differ with spectral regions incident on the skin, thus affecting local and remote effects on the sweating response.     

Role of electrostatic repulsion in the acidic molten globule of cytochrome c.

The molten globule has been assumed to be a major intermediate state of protein folding. To extend our understanding of protein folding it is important to elucidate the thermodynamic mechanism of conformational stability of the molten globule. To clarify the role of electrostatic charge repulsion in the stability of the acidic molten globule state, we prepared a series of acetylated horse ferricytochrome c species with various degrees of charge repulsion. On the basis of circular dichroism measurement, we show that the stability of the acidic molten globule is determined by a balance of electrostatic repulsions between positive residues, which favor the extended conformation, and the opposing forces, which stabilize the molten globule. These results provide a clear example of charge repulsions producing unfolding of the compact protein structure, and suggest that the reversibly denatured conformation of ferricytochrome c under physiological conditions (i.e. neutral pH, ambient temperature and no denaturant) is the molten globule.