NIRS PREDICTION FOR PROTEIN AND INTRAMUSCULAR FAT CONTENT OF RABBIT HIND LEG MEAT

The goal of this study was to develop calibration equations to predict the chemical composition of raw, homogenized rabbit meat by means of near infrared spectroscopy (NIRS). 44 Pannon White rabbits were housed in groups in three different pen types (16 anim./m2), and were fed the same diet. Another 45 animals were housed in cages (12 anim./m2) and fed by different feeding regimes. Rabbits were slaughtered at the bodyweight of 2.4-2.5 kg. Homogenized fresh and freeze-dried left total hind leg muscles were investigated by NIRS using a NIRSystem 6500 equipment with small ring cup sample holder. The ether extract and protein content of all samples were determined chemically. Samples 44 of housing experiment were applied in producing LOCAL calibration equations tested on the 45 samples from the separate feeding experiment. Coefficients of determination (R2) of the predictions were 0.89 and 0.99 for fat, 0.85 and 0.96 for protein in fresh and freeze-dried samples, respectively. Results are reassuring, because the equations were applicable, however the analyzed samples were from independent housing and feeding systems. Therefore the chemical compositions differed in the two datasets, i.e. 9.46%, and 11.79% for fat, 85.75% and 83.44% for protein content in calibration and prediction datasets, respectively. The average of NIRS predicted values for fat and protein was 11.36%, 83.88% or 11.54%, 83.45% when using fresh or freeze-dried samples, respectively

Letter to the Editor: 1H and 15N sequential assignment and solution secondary structure of 15N labelled human pancreatic ribonuclease

Several members of the RNase A (bovine pancreatic ribonuclease) superfamily exhibit anticancer activity. Among the mammalian members of the superfamily, most of the antitumour activity studies have been carried out with a dimeric RNase from bovine seminal vesicles (BS-RNase) (Youle and D’Alessio, 1997). These studies show that dimer formation is crucial for cytotoxicity. Investigations are underway to transfer by protein engineering the structural determinants responsible for the antitumour activity of BS-RNase to a human immunocompatible backbone (Piccoli et al., 1999). Knowledge of the 3D structures of the involved proteins is central to rationally fulfil this objective. As a first step, human pancreatic ribonuclease (HPRNase), a 127-residue monomeric protein (Beintema et al., 1984) was constructed (Russo et al., 1993). The expressed recombinant protein was undistinguishable from the natural product isolated from human pancreas (Weickmann et al., 1981). Here, we present the assignment of practically all of its 1H and 15N spectral resonances, as well as its secondary structure in aqueous solution. The cytotoxic activity of ribonucleases has been related to their ability to evade the cytosolic ribonuclease inhibitor (RI) (Murthy and Sirdeshmukh, 1992). The structure of HP-RNase will be useful to introduce changes in it in order to increase its resistance to RI.This work was supported by the European Commission under the INCO-Copernicus Project No. IC15 CT 96-0903. The assistance of the Ministerio de Asuntos Exteriores (Spain) and OMFB (Hungary) (project E26/97) is gratefully acknowledged

The Solution Structure and Dynamics of Human Pancreatic Ribonuclease Determined by NMR Spectroscopy Provide Insight into Its Remarkable Biological Activities and Inhibition

Human pancreatic ribonuclease (RNase 1) is expressed in many tissues; has several important enzymatic and biological activities, including efficient cleavage of single-stranded RNA, double-stranded RNA and double-stranded RNA–DNA hybrids, digestion of dietary RNA, regulation of vascular homeostasis, inactivation of the HIV, activation of immature dendritic cells and induction of cytokine production; and furthermore shows potential as an anti-tumor agent. The solution structure and dynamics of uncomplexed, wild-type RNase 1 have been determined by NMR spectroscopy methods to better understand these activities. The family of 20 structures determined on the basis of 6115 unambiguous nuclear Overhauser enhancements is well resolved (pairwise backbone RMSD = 1.07 Å) and has the classic RNase A type of tertiary structure. Important structural differences compared with previously determined crystal structures of RNase 1 variants or inhibitor-bound complexes are observed in the conformation of loop regions and side chains implicated in the enzymatic as well as biological activities and binding to the cytoplasmic RNase inhibitor. Multiple side chain conformations observed for key surface residues are proposed to be crucial for membrane binding as well as translocation and efficient RNA hydrolysis. 15N–1H relaxation measurements interpreted with the standard and our extended Lipari–Szabo formalism reveal rigid regions and identify more dynamic loop regions. Some of the most dynamic areas are key for binding to the cytoplasmic RNase inhibitor. This finding and the important differences observed between the structure in solution and that bound to the inhibitor are indications that RNase 1 to inhibitor binding can be better described by the “induced fit” model rather than the rigid “lock-into-key” mechanism. Translational diffusion measurements reveal that RNase 1 is predominantly dimeric above 1 mM concentration; the possible implications of this dimeric state for the remarkable biological properties of RNase 1 are discussed.This work was supported by projects OTKA NK 68578 from the Hungarian Research Foundation and BFU2005-01855/BMC from the Spanish Ministerio de Educación y Ciencia

Target ionization and projectile electron loss in simple collision systems

Absolute double differential cross sections for target ionization and projectile electron loss were measured in collisions of H+, H+ 2, 3He+ and 3He++ (0.4 to 2.0 MeV/u) with He and Ar at electron emission angles from 0° up to 60°. The experimental results are qualitatively well described by plane wave Born approximations including projectile screening.Nous avons mesuré les sections efficaces absolues doublement différentielles pour l'ionisation de la cible et la perte d'électrons du projectile, lors de collisions de H+, H+2, 3He+ et 3He ++ (0,4 à 2,0 MeV/u) contre He et Ar, à des angles d'émission des électrons compris entre 0° et 60°. Les résultats expérimentaux sont qualitativement bien décrits par l'approximation de l'onde plane de Born en tenant compte des effets de blindage du projectile

Lithofacies and age data of Jurassic foreslope and basin sediments of Rudabanya Hills (NE Hungary) and their tectonic interpretation

Jurassic sedimentary rocks of the Telekesvölgy Complex (Bódva Series), Telekesoldal Complex (Telekesoldal Nappe) and the Csipkés Hill olistostrome in Rudabánya Hills (NE Hungary) were sampled for microfacies studies and interpretation of the depositional environments. The Telekesvölgy Complex is made up of reddish to greenish marl, occasionally containing limestone olistoliths — gradually progresses from the Norian Hallstatt Limestone of the Bódva Series — then grey marl, which may correspond to the latest Triassic Zlambach Formation. This variegated marl progresses into grey marl and calcareous marl, containing crinoid fragments. It may be interpreted as a hemipelagic facies, relatively close to submarine highs. Bajocian to Lower Bathonian black shales, rich in radiolarians and sponge spicules representing typical deep pelagic facies, are also assigned to the Telekesvölgy Complex. The Telekesoldal Complex represents a mélange-like subduction-related complex that consists of black shales, sandstone turbidites and olistostrome beds, and deposited by gravity mass flows. A relatively deep marine basin in the proximity of a submarine slope is likely to be the depositional environment of this unit. The clasts of the olistostromes are predominantly Middle to Upper Triassic pelagic limestones, rhyolite and basalt. Subduction related nappe stacking of the ocean margin during the Middle to Late Jurassic may have created suitable conditions for this sedimentation pattern. Bajocian-Callovian age of the complex was proved by the revision of the radiolarian fauna and new palynological data, the first from the Jurassic of the Aggtelek-Rudabánya Hills. The Csipkés Hill olistostrome consists of carbonate turbidite beds containing Jurassic platform derived foraminiferal and olistostrome horizons with Middle-Upper Triassic limestone clasts of red Hallstatt facies