Isolation from earthworms of a proteinaceous chemoattractant to garter snakes

We have isolated a potent proteinaceous chemoattractant from aqueous washes of earthworm (Lumbricus terrestris) for garter snakes (Thamnophis sirtalis) by means of a covalent chromatography. It contained free sulfhydryl groups and showed an apparent mass of 20 kDa. The chemoattractive activity of this protein could be destroyed by heating as well as by proteolysis. Its activity could also be reversibly blocked by mixed disulfide formation with dithiodipyridine, suggesting that the free sulfhydryl(s) was essential for its function as a chemoattractant. This bioactive material had a tendency to form intermolecular crosslinked aggregates during isolation, if reducing agents were not included. Some of the high-molecular-weight aggregates cochromatographed with earthworm cuticle collagen on Ultragel AcA 34 or 44 columns. In contrast to an earlier report by D. M. Kirschenbaum, N. Schulman, and M. Halpern [1986) Proc. Natl. Acad. Sci. USA 83, 1213-1216) the purified earthworm collagen showed no chemoattractive activity to garter snakes.     

Chronic urticaria.

Urticaria affects 15% to 20% of the population once or more during a lifetime. Chronic urticaria is a frequent recurrent eruption over a period greater than 6 weeks; the cause remains a mystery in more than 75% of cases. Urticaria and angioedema may be produced by immunologic or nonimmunologic means. Urticarial vasculitis, contact urticaria, mastocytosis, physical urticarias, dermatographism, cholinergic urticaria, localized heat urticaria, cold urticaria, aquagenic urticaria, and vibratory angioedema all require specific evaluation and treatment. Chronic idiopathic urticaria is usually controlled by antihistamines; depending on the circadian rhythm of the eruption, sedative or nonsedative antihistamines are prescribed. Some patients will require a combination of H1 and H2 antagonists, or even parenteral corticosteroids.     

Purification and properties of glutamate binding protein from the periplasmic space of Escherichia coli K-12.

Glutamate binding protein released from the periplasmic space of Escherichia coli K-12 by lysozyme-EDTA treatment was purified to homogeneity and its physical and chemical properties were studied. It is a basic protein with a pI of 9.1. Its molecular weight, determined in an analytical ultracentrifuge, and by gel filtration on Sephadex G-100 and dodecylsulphate acrylamide is 29 700, 27 800 and 32 000, respectively. The KD value for glutamate was 6.7 - 10- minus 6 M. L-Aspartate, reduced glutathione, G-glutamate-gamma-benzylester and L-glutamate-gamma-ethylester competitively inhibited glutamate binding with K-i; values of 7.8 - 10- minus 5, 1.1 - 10- minus 5, 1.0 - 10- minus 5 and 1.0 - 10- minus 5 M, respectively. Spheroplasts retained 40% of glutamate transport as compared to intact cells. The glutamate binding activity of a glutamate-utilizing strain (CS7), was 1.6 times as high as that of the glutamate non-utilizing parent strain (CS101). Similarly, the glutamate binding activity of a temperature conditional glutamate-utilizing mutant (CS2-TC) was 1.9 times higher when grown at the permissive temperature (42 degrees C) than when grown at the restrictive temperature (30 degrees C).     

The Location and Protection Status of Earth’s Diminishing Marine Wilderness

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