A 3.5 gram quantity of β-(1→4)-glucan cellobiohydrolase C was purified from a commercial Trichoderma viride culture filtrate preparation, Meicelase P. Compared to the A and B forms, the C form of the cellobiohydrolase is present in the crude enzyme preparation in greater quantity and has a higher affinity for microcrystalline cellulose at pH 5. The C form was separated from the other forms by adsorption on a cellulose column, Following elution from the column, the cellobiohydrolase C was separated from other cellulose-adsorbed proteins by a batch separation on DEAE-Sephadex. The cellobiohydrolase C bound to the anion exchange at pH 5.0 is homogeneous by disc gel electrophoresis and identical to the "C₁" enzymes, F-II cellulase and hydrocellulase C, purified previously in this laboratory. Purified cellobiohydrolase C has an E₂₈₀^1% = 14.2and degrades both microcrystalline and phosphoric acid-swollen cellulose to cellobiose at the rates of 213 and 738 nmoles minute⁻¹ mg protein⁻¹, respectively. The cellobiohydrolase C contains 30.0, 5,5, 2,7 and 3.9 moles of mannose, glucose, galactose and glucosamine, respectively, per mole of enzyme (molecular weight 55,000). Methylation analysis of cellobiohydrolase glycopeptides indicates an average carbohydrate chain length of two residues. Consistent with the idea of several short carbohydrate chains is the release by alkaline borohydride treatment of cellobiohydrolase C of 89% of the neutral carbohydrate which is bound through an average of 19.4 0-glycosidic linkages to serine and threonine per molecule of enzyme, Glucosamine was not released from the protein by alkaline treatment suggesting a 4'-N-(2-acetamido-2-deoxy)-β-D-glucopyranosyl-L-asparagine linkage, Such an N-glycosidic linkage is consistent with the results of fractionation of the cellobiohydrolase glycopeptides by high voltage paper electrophoresis, filtration and paper chromatography which demonstrated that the glucosamine residues and the majority of the neutral carbohydrate are bound in different oligosaccharide chains. Only half of the glucosamine residues were destroyed by periodate oxidation pointing to the possible existence of both substituted di-N-acetylchitobiose units such as those found in other glycoproteins and unsubstituted single residues of glucosamine bound to the asparagine residues. Analysis of alkaline borohydride-released carbohydrate by high pressure liquid chromatography demonstrated that an average enzyme molecule contains 10,9 mono-, 2,0 di-, 4.9 tri-, and 1.2 tetra- and 0.4 pentasaccharide chains, The base stability of the linkages between the neutral monosaccharide residues in the chains and the destruction of all neutral carbohydrate periodate suggests that the (1→2) linkage is present but does not rule out the (1→6) linkage. Action of α-mannosidase indicates that at least some oligosaccharide chains contain α-mannose as the terminal residue, / Ph. D.

New cis-dichloro ruthenium-based pre-catalysts for olefin metathesis reaction were synthesised. This work was inspired by the report of complex cis-Caz-1 in 2010, a 2nd generation-type pre-catalyst displaying latent character and acknowledged as state-of-the-art for challenging transformation in olefin metathesis. The stability and the reactivity of such species led us to investigate the possibility to perform the catalysis in air with reagent-grade solvents, so that olefin metathesis reaction can be easily carried out in synthetic laboratories avoiding restricting inert conditions (Chapter 2). Next, further modifications of the original scaffold were attempted. Pre-catalyst cis-Caz-1 was reacted with different silver salts leading to new cis-complexes. The first examples of Ru-F species for olefin metathesis reaction are reported in Chapter 3. The phosphite ligand plays a very important role in the cis-Caz-1 scaffold and allowed the formation of the mono and the difluoro complexes selectively. Other silver salts were then employed such as trifluoroacetate, acetate, benzoate and pivalate. In all the studies involving silver salts, the anionic exchange reactions occurring among cis-Ruspecies in solution was observed. Electronic properties rather than sterics were responsible for the selective formation of the mixed complex trifluoroacetate/acetate 55 (Chapter 4). The results obtained with 2nd generation systems prompted us to evaluate triisopropyl phosphite as ligand in 1st generation-type complexes. Similar synergistic effects to complex cis-Caz-1 were observed. The mixed PCy3/P(OiPr)3 complex 56 displayed cis-geometry, high thermal stability and latent character compared to the bis-phosphine analogue Ind-I (Chapter 5). Last, a catalytic and structural study of commercially available pre-catalysts M51TM and M52TM in collaboration with Umicore was carried out together with the Grela group (Chapter 6). These Hoveyda-Grubbs type pre-catalysts showed an interesting activity in ring closing metathesis, allowing the isolation of di- and tri- substituted ring-products at room temperature, as well as in cross metathesis, where some examples of biologically active compounds were obtained.

Thesis (B.S.)--Massachusetts Institute of Technology, Dept. of Humanities, 1964. / MIT Archives copy bound with: The relevance of some recent experiments on perception in infants to the philosophical concept of space as an innate idea / Thomas Henry Daniel. 1964. / Field of Humanities and Engineering (Course XXI-A). Includes International architecture. 2nd altered ed. Munich, ALbert Langen Verlag, 1925 (No.1 of the Bauhausbücher) Text by Walter Gropius. Translated by K.H. Kaiser (p.31-34) / B.S.

Recent mainstream economic theory has been almost totally confined to analyzing situations in which the rules of the game are fully defined. Such rules ordinarily limit the types of social interaction which can occur. In particular, the vast majority of economic writings consist of an indefinite number of variations on one simple interaction form: exchange. There are many other widely prevalent forms of interaction, however. These include extortion, theft, congestion, and charitable gifts. In principle, there is no reason why the sophisticated language and analytical techniques of exchange theory cannot be applied to these less fashionable types of social contact, although such application is not easy. The purpose of the dissertation is to demonstrate the widespread relevance of analytical techniques which have previously been associated primarily with economic exchange theory. The second chapter of the dissertation, entitled "Social Choice in Anarchy," is concerned with the construction of an operational definition· of social interaction. Since purposeful social interaction can be said to be precipitated by external effects, it begins by presenting a typology of external effects in a simple two-person model. Since social interaction also requires knowledge of reciprocity, the chapter proceeds with a discussion of the difficulties that are associated with incorporating the concept of knowledge into analytical models. A model of social interaction is also a model of institutional formation, since institutional mechanisms arise either as a result of, or in anticipation of, social interaction. Chapter III, "The Government as an Institution of Social Choice," and Chapter IV, "The Monetary System as an Institution of Social Choice," show how the model of social choice developed in Chapter II can be used to construct a useful definition of these particular institutions. The definition of government goes one step beyond that developed by Buchanan and Tullock and by Downs and that which is used implicitly in the economic literature on property rights. It explicitly recognizes the potential redistributive effects of government as a coercive institution and incorporates these effects into the definition. A somewhat different approach is taken with respect to the monetary system, although the principles employed are identical. The current system is compared with a theoretical construct which is based solely on the ability of a monetary system to raise the efficiency of exchange. The demonstrated differences between the two can be attributed to the redistributive effects of a monetary system which is supported by a coercive authority. Chapter V, "An Economic Approach to Riot Analysis," analyzes a somewhat different type of social phenomenon, that of riots. Although rioting is a form of social interaction, it is not usually defined as an institution. Yet, it is only through a proper definition that one can proceed to meaningfully evaluate and predict riots. The model of social interaction developed in Chapter II is used implicitly to analyze riots within the context of attempting to solve the practical problem of how to prevent them. / Ph. D.

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