Preparation of photodynamic hydrolysates from bovine hemoglobin Celpel, N. (Laboratoire de Technologie des Substances Naturelles, Villeneuve d'Ascq, France.); Piot, J.M; Guillochon, D
Journal of agricultural and food chemistry,
09/1994, Letnik:
42, Številka:
9
Journal Article
Recenzirano
Porphyric peptides were prepared from an agricultural byproduct, bovine hemoglobin. Hemoglobin was hydrolyzed with alcalase. After removal of heme iron, the total hydrolysate was separated on gel ...filtration. It consisted of three fractions; the major one was separated by reversed-phase performance chromatography. FAB analysis indicated that protoporphyrin, hematoporphyrin, and hydroxyethylvinyl deuteroporphyrin were the major porphyrin constituents. These porphyrins were maintained in solution by peptidic hydrolysates. The hydrophilic and photosensitizing properties of porphyrin-peptide complexes were demonstrated. The water-solubilizing ability of hydrolysates was significant and allowed amphiphilic porphyrins to be obtained. These compounds could give applications in different fields: they could be employed as insecticides and antibacterial products or even could give, after further purification, application in photodynamic therapy
L'intérêt de ces études est de favoriser l'apparition de peptides a activités biologiquesau cours de l'hy droly se de l'hémoglobine.La fixation de la pepsine sur l'alumine a permis d'observer une ...modification de la sélectivité de la réaction d'hy droly se de l'hémoglobine : l'accumulation d'une population peptidique intermédiaire de haute masse moléculaire est favorisée par rapport à la réaction menée en phase homogène (Figure 4,5). Avec lapepsine immobilisée sur l'alumine native et fonctionnalisée, il a été observe que la vitesse d'hy droly se de la VV-hémorphine 7 est ralentie comparée à la réaction menée en phase homogène. Enfin, après immobilisationde la pepsine sur native et fonctionnalisée, une production considérablement accélérée de la néoky otorphine a été mise en évidence.
Gel-permeation high-performance liquid chromatography (HPLC) and reversed-phase HPLC were used to separate a mixture of peptides, produced at pilot-plant scale by peptic hydrolysis of bovine ...haemoglobin. Volatile buffers were employed in both HPLC techniques in order to get an easy recovery of peptides for further applications. The method is more rapid than low-pressure gel filtration. Amino acid analysis and fast atom bombardment mass spectrometry confirmed the purity, and allowed accurate molecular weights to be determined, for isolated peptides. These data demonstrate that such efficient techniques, usually used to resolve hydrolysates obtained in batch with pure substrates and highly specific enzymes, can be employed to resolve complex enzymatic hydrolysates of crude protein.
L'O.M.C, un premier bilan Guillochon, Bernard
Revue française d'économie,
1997, Letnik:
12, Številka:
4
Journal Article
Odprti dostop
L'O.M.C. bénéficie actuellement d'une plus grande légitimité que le G.A.T.T. En témoignent les demandes d'adhésion et le nombre élevé de conflits commerciaux portés devant ses organes de règlement ...des différends. Mais la réussite de l'О.М.С. n'est pas garantie. Elle dépendra de sa capacité à faire appliquer les nouvelles mesures de libéralisation du commerce : abaissement des droits de douane et, surtout, réduction des subventions, limitation des mesures de sauvegarde, défense de la propriété intellectuelle, réduction des protections sur l'agriculture et sur les textiles. La suppression des obstacles sur les services, souhaitée initialement par les pays développés, reste partielle. Les services de télécommunication ont fait l'objet d'un accord tardif (février 1997) et il n'y a toujours pas d'entente dans les services financiers. D'autres questions restent en suspens (clause sociale, environnement, investissement direct étranger).
The W.T.O. is currently enjoying a legitimacy unmatched by the G.A.T.T., as witnessed by the number of applications for entry and the high number of trade disputes which are brought before its settlement committees. But the success of the W.T.O. is not warranted. It will depend on its ability to enforce the new provisions for a free trade : a lowering of customs tariffs and especially a decrease in subsidies, a curtailment in the number of safeguard mesures, a defense of intelectual property rights, a reduction in protection mechanisms for agriculture and textiles. A removal of the obstacles on services first wished for, by highly industial countries, has been only partly achieved. Only recently was achieved a long awaited-for agreement on telecommunications services (february 1997), and there is still no agreement on financial services. Other issues are still pending (labour protection rules, foreign direct investment).
Dans la période 1970-1977, le degré moyen de protection nominale et effective de la France a diminué. Ceci ne doit pas faire croire qu'on se trouve sur le point d'abandonner toute forme de ...protectionnisme. On constate en effet que certains produits spécifiques comme les textiles et l'habillement, les cuirs et chaussures et les biens d'équipement ménager bénéficient d'une augmentation des taux nominaux et effectifs dans la période. On observe en plus que le mouvement d'abaissement des droits sur les autres biens ne se fait pas de façon uniforme, la branche automobile étant caractérisée par une réduction relativement plus faible que les industries agro-alimentaires et les biens intermédiaires. De plus dans de nombreux secteurs, il y a hausse du taux effectif, soit à cause de l'augmentation des taux nominaux, soit à cause de l'allégement de la tarification sur les inputs (énergie, métaux, services). Parallèlement on constate, dans notre pays comme ailleurs, un développement des obstacles non tarifaires (contingentements, normes techniques, autorisations administratives) qui concernent particulièrement les biens manufacturés et les importations en provenance de zones extérieures à l'OCDE. /// During the period 1970-1977 average rates of nominal and effective protection of France decreased. This does not mean we are about to give up any form of protectionism. As a matter of fact, nominal and effective rates increased in several industries like textile, clothing, leather, shoes and consumer durables. In the other industries there is reduction of tariffs but of variable extent: small for cars, high for processed food and intermediate products. When increasing of effective tariffs exists, it is induced by increasing of nominal tariffs on final goods or by lowering of tarification on inputs (energy, metals, services). In France, like outside, non tariff barriers are used more and more (quotas, government regulations, government restrictions). More often these barriers apply to manufactured goods and to imports from developing and socialist countries.
Catalytic activities of bovine hemoglobin Matcham, G W; Chapsal, J M; Guillochon, D
Annals of the New York Academy of Sciences,
June 1987, Letnik:
501
Journal Article
While gas accretion onto some massive black holes (MBHs) at the centers of galaxies actively powers luminous emission, the vast majority of MBHs are considered dormant. Occasionally, a star passing ...too near a MBH is torn apart by gravitational forces, leading to a bright panchromatic tidal disruption flare (TDF). While the high-energy transient Swift J164449.3+573451 ("Sw 1644+57") initially displayed none of the theoretically anticipated (nor previously observed) TDF characteristics, we show that the observations (Levan et al. 2011) suggest a sudden accretion event onto a central MBH of mass ~10^6-10^7 solar masses. We find evidence for a mildly relativistic outflow, jet collimation, and a spectrum characterized by synchrotron and inverse Compton processes; this leads to a natural analogy of Sw 1644+57 with a smaller-scale blazar. The phenomenologically novel Sw 1644+57 thus connects the study of TDFs and active galaxies, opening a new vista on disk-jet interactions in BHs and magnetic field generation and transport in accretion systems.
