Christian Betzel

L -Amino-acid oxidase from the venom of Vipera ammodytes ammodytes, the most venomous snake in Europe, was isolated and crystallized using the sitting-drop vapour-diffusion method. The solution conditions under which the protein sample was monodisperse were optimized using dynamic light scattering prior to crystallization. The crystals belonged to space group C2, with unit-cell parameters a = 198.37, b = 96.38, c = 109.11 Å, = 92.56°. Initial diffraction data were collected to 2.6 Å resolution. The calculated Matthews coefficient is approximately 2.6 ų Da^-1 assuming the presence of four molecules in the asymmetric unit.

The venom proteomics of Vipera ammodytes ammodytes and Vipera ammodytes meridionalis, snakes of public health significance and the most poisonous reptiles in Europe, were analyzed by FPLC, 2-D electrophoresis, sequence analysis, and MS/MS. FPLC analysis showed the presence of l-amino acid oxidase, monomeric and heterodimeric phospholipases A₂, C-type lectin protein, and proteinases in the venom of V. a. ammodytes. Representatives of the same protein families were found in the venom of the other subspecies, V. a. meridionalis. N-terminally identical PLA₂ neurotoxins were identified in both venoms. Difference in the PLA₂ compositions of the venoms was also observed: a monomeric protein with phospholipase A₂ activity, identical in the first 20 amino acid residues to the catalitically inactive acidic component of the heterodimeric PLA₂ present in both venoms, was found only in that of V. a. meridionalis. Probably, this protein represents an intermediate form of the two components of the heterodimer. 2-D electrophoresis and MS/MS analysis showed that the two venoms shared a number of protein families: monomeric and heterodimeric Group II PLA₂s, serine proteinases, Group I, II, and III metalloproteinases, l-amino acid oxidases (LAAOs), cysteine-rich secretory proteins, disintegrins, and growth factors. Totally, 38 venom components of the V. a. ammodytes, belonging to 9 protein families, and 67 components of the V. a. meridionalis venom belonging to 8 protein families were identified. The venom proteome of V. a. ammodytes shows larger diversity of proteins (139) in comparison to that of V. a. meridionalis (104 proteins). Most of the proteins are homologues of known representatives of the respective protein families. The protein compositions explain clinical effects of the V. ammodytes snakebites, such as difficulties in the breathing, paralysis, apoptosis, cloting disorders, hemorrhage, and tissue necrosis. The lists of secreted proteins by the two vipers can be used for further study of structure–function relationships in the toxins and for prediction and treatment of snakebite consequences.

The homochirality of biomolecules is a prerequisite for the origin and evolution of terrestrial life. The unique selection of D-monosaccharides, in particular, D-ribose in RNA and D-deoxyribose in DNA, leads to the construction of proteins by L-amino acids. This points to the exclusive role of stereoselectivity in the most important physiological processes. So far, there is no experimental confirmation for the theoretical calculations of the energy differences between enantiomers used for the explanation of the stereoselection of biomolecules. Therefore, the question of why nature prefers one configuration over the other still lacks a definitive answer. Here, we present the first experimental evidence that the D-enantiomer of RNA has a different electronic structure compared to the corresponding L-enantiomer. When varying the incident photon energy of the ultraviolet Raman probe across 5 eV, D- and L-isomers of the RNA duplex with the sequence [r(CUGGGCGG).r(CCGCCUGG)] show differences in the intensity of the vibrational modes with energies of 124.0 meV to 210.8 meV. The intensity difference of these vibrational modes can be traced back to energy differences in the electronic levels of D- and L-RNA leading to the preferential stabilization of the naturally occurring D-configuration of RNA over the L-configuration.

The digestive fluid of the marine crab Cancer pagurus (Decapoda, Brachyura) contains highly stable proteases which display enhanced activity in aqueous mixtures of organic solvents. Three trypsins were isolated from the gastric fluid and two of them, C.p.TryII and C.p.TryIII, were purified to homogeneity by anion-exchange chromatography and crystallized by hanging-drop vapour diffusion. Diffraction data were collected at a synchrotron to 0.97 and 3.2 Å resolution, respectively. The crystal of C.p.TryII belongs to the orthorhombic space group P2₁2₁2₁, with unit-cell parameters a = 52.06, b = 62.00, c = 71.66 Å. Based on the Matthews coefficient, one protein molecule per asymmetric unit is suggested. In contrast, crystals of C.p.TryIII, which belong to the cubic space group P2₁3 with unit-cell parameters a = b = c = 215.4 Å, are assumed to contain 12 molecules per asymmetric unit.