Bradykinin-potentiating peptide from venom of the spider Latrodectus tredecimguttatus

A bradykinin-potentiating peptide has been isolated from the venom of the spiderLatrodectus tredecimguttatus. Its physicochemical properties and amino acid composition have been investigated in detail. It has been shown by biological testing on isolated neck of the rat uterus that the peptide increases the contractile effect of bradykinin in in vitro experiments. The potentiating unit is 2 · 10^–3 mg/ml. A 50% increase in the hypotensive effect of bradykinin at a concentration of the bradykinin-potentiating peptide of 15 µg/kg of body weight has been found, the increase in the intensity of the effect being accompanied by a prolongation of its action.A. Sadykov Institute of Bioorganic Chemistry, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 699–703, September–October, 1989.     

Isolation of α-latrotoxin from venom of the spider Latrodectus tredecimguttatus by affinity chromatography

An affinity method is decribed for isolating -latrotoxin, a neurotoxin with a presynaptic action from the venom of the spiderLatrodectus tredecimguttatus, by two different antibody immunosorbents enabling the neurotoxin to be obtained in the homogeneous state according to the result of immunoelectrophoresis and electrophoresis in polyacrylamide gel after one chromatographic isolation. The first immunosorbent consisted of monospecific antibodies to -latrotoxin bound to the F_c fragment of protein of protein A fromStaphylococcus aureus which, in its turn, was covalently conjugated with a cellulose sorbent — Tsellopor; and the second consisted of the active F_ab fragments of the same antibodies covalently conjugated with Tsellopor. It was shown that the capacity of the F_ab-Tsellopor immunosorbent was 1.5–2.0 times higher than the capacity of the antibody-protein A-Tsellopor immunosorbent.A. S. Sadykov Institute of Bioorganic Chemistry, Uzbek Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 679–682, September–October, 1988.     

Dehydroalanine-based inhibition of a peptide epimerase from spider venom

Ribosomally produced peptides that contain D-amino acids have been isolated from a number of vertebrate and invertebrate sources. In each case, the D-amino acids are introduced by a posttranslational modification of a parent peptide containing only amino acids of the L-configuration. The only known enzyme to catalyze such a reaction is the peptide epimerase (also known as peptide isomerase) from the venom of the funnel web spider, Agelenopsis aperta. This enzyme interconverts two 48-amino-acid-long peptide toxins that differ only by the stereochemistry at a single serine residue. In this paper we report the synthesis and testing of two pentapeptide analogues that contain modified amino acids at the site normally occupied by the substrate serine residue. When the L-chloroalanine-containing peptide 3 was incubated with the epimerase it was converted into the dehydroalanine-containing peptide 4 via an elimination of HCl. The dehydroalanine peptide 4 was independently synthesized and found to act as a potent inhibitor of the epimerase (IC50 = 0.5 microM). These results support a direct deprotonation/reprotonation mechanism in which a carbanionic intermediate is formed. The observed inhibition by 4 can be attributed to the sp(2)-hybridization of the alpha-carbon in the dehydroalanine unit that mimics the planar geometry of the anionic intermediate.     

Bradykinin-potentiating peptides fromEchis multisquamatus venom

Eight bradykinin potentiating peptides have been isolated in the pure form from the low-molecular-mass fraction of the venom of the Central Asian viper Echis multisquamatus Ch. The peptides isolated differed in the efficacy of their bradykinpotentiating activity and their capacity for inhibiting the angiotensin-converting enzyme (ACE, EC 3.4.15.1); however, complete correlation of the two activities was established for only six of them.Institute of Biochemistry, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (3712) 62 32 56. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 435–440, May–June, 1995.     

Phospholipase A2 from the venom of the spider Eresus niger

A phospholipase A₂ with a molecular mass of 12–14 kDa has been isolated from the venom of the spiderEresus niger by three-stage column chromatography. Asparagine has been identified as the N-terminal amino acid.     

Phospholipase A2 from the venom of the spider Eresus niger

A phospholipase A₂ with a molecular mass of 12–14 kDa has been isolated from the venom of the spiderEresus niger by three-stage column chromatography. Asparagine has been identified as the N-terminal amino acid.Institute of Physiology, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 557–560, July–August, 1991.     

Comparative Biochemistry of the Physiologically Active Components of Venom, Hemolymph, and Eggs of the Karakurt Spider (Latrodectus tredecimguttatus)

The physicochemical and functional properties of the venom, hemolymph, and egg extract of the karakurt spiderLatrodectus tredecimguttatuswere studied. A highly purified toxin that differs from the neurotoxins found previously in the venom was isolated from the hemolymph and characterized.     

Characterization and synthesis of a new calcium antagonist from the venom of a fishing spider

A new calcium antagonist, CNS 2103, is isolated from the venom of a fishing spider, Dolomedes okefinokensis. The structure of this compound is derived from spectroscopic data, including tandem mass spectrometry. A flexible, convergent synthesis of CNS 2103 is described.     

Structure and enantioselective synthesis of polyamine toxin MG30 from the venom of the spider Macrothele gigas

A novel polyamine toxin, named MG30, was isolated from the venom of the spider, Macrothele gigas, and its structure was elucidated by two-dimensional NMR and mass analysis. In addition, the enantioselective synthesis of MG30 was achieved to assign its absolute stereochemistry.     

A new approach to natural products discovery exemplified by the identification of sulfated nucleosides in spider venom

Using a new approach based on the NMR spectroscopic analysis of the entire, unpurified spider venom, we identified a family of unusual sulfated nucleoside derivatives from the venom of the hobo spider, Tegenaria agrestis. These compounds are ribonucleoside mono- and disulfates derived from guanosine and xanthosine, some of which are glycosylated, bearing one or two D-fucose units. The use of NMR spectroscopy to characterize the unfractionated venom was central to the discovery of this heretofore overlooked class of venom components.     

Cardanolides from the Chinese toad venom Ch'an Su

From the toad venom Ch'an Su the cardenolides I, III and V have been isolated. It is the first time that cardenolides and bufadienolides are detected simultaneously in a biological material.     

Stereospecificity of a lysophospholipase from the venom ofVespa orientalis

Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (3712) 89 14 75. Institute of Physiology and Biophysics, Academy of Sciences of the Republic of Uzbekistan, 700095, Tashkent, ul. Niyazova, 1. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 625–627, July–August, 1995. Original article submitted November 9, 1994.     

The components of the venom of a spider Scodra griseipes. 2. Structural information on biogenic amines using tandem mass spectrometry.

Biogenic amines, which are components of tarantula Scodra griseipes venom, are studied using tandem mass spectrometry. Their heptafluoropropionic (PFP) derivatives are ionized under electron impact and isobutane-chemical ionization. Daughter- and parent-ion mass spectra under collisionally activated dissociation conditions provide a more detailed study of such derivatives. Discrimination of di(PFP)amines and tri and tetra(PFP)amines is possible because of the presence of diagnostic ions induced by collision.     

Isolation of a ca-channel blocker from the venom of the spiderAgelena labirintica

From the venom of the spider Ageiena labirintica we have isolated the neurotoxin Agll (IV-6-1) with a molecular mass of 1000 Da, which effectively blocks the Ca channels of presynaptic membranes of frog nerve-muscle synapses.Institute of Physiology and Biophysics, Academy of Sciences of the Republic of Uzbekistan, 700095, Tashkent, ul. Niyazova, 1. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 467–470, May–June, 1995. Original article submitted October 24, 1994.     

Studies on the insolubility of a transmembrane peptide from signal peptide peptidase

We have undertaken fundamental studies on the solubility properties of a peptide derived from the fourth transmembrane (TM) domain of signal peptide peptidase, a 7-TM intramembrane-cleaving protease. We have found that by disfavoring secondary structure formation we are able to greatly improve the solubility, handling, and purification properties of this peptide. Our findings suggest that preventing secondary structure formation by reversible modification of the polypeptide backbone of hydrophobic transmembrane peptides may be a useful strategy for the total chemical protein synthesis of integral membrane proteins.     

Mechanical and thermal properties of dragline silk from the spider Nephila clavipes

Dragline silk from the spider, Nephila clavipes, was characterized by thermal analysis (TGA, DSC, DMA), computational modeling, scanning electron microscopy and by quasi-static as well as high rates of strain. Thermal stability to about 230°C was observed by TGA, two transitions by DMA, ?75°C, representative of localized motion in the amorphous domain, and a main chain motion associated with partial melt at 210°C. Tensile tests indicated average initial modulus, ultimate tensile strength and ultimate tensile strain of 22 GPa, 1.1 GPa and 9%, respectively. The corresponding properties of the best fibers tested were 60 GPa, 2.9 GPa and 11%, respectively. High strain rates (>50,000%/sec) indicated similar mechanical properties to the average values indicated above. Microscopy showed compressive and tensile strains to failure of 34%. Computational modeling yielded a crystal modulus of 200 GPa.     

Competitive inhibitors of the angiotensinconverting enzyme from the venom of the viperEchis multisquamatus

The mechanism of the inhibition of the angiotensin-converting enzyme (ACE, E. C. 3.4.15.1) by homogeneous peptides of the venom of the Central Asian viperEchis multisquamatus Ch. has been determined, and the inhibition constants have been measured, by means of an analysis of Lineweaver-Burk graphs.Institute of Biochemistry, Academy of Sciences of the Republic of Uzbekistan, Tashkent fax (3712) 62 32 56. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 368–371, May–June, 1999.