83 research outputs found
Elliptic hypergeometry of supersymmetric dualities II. Orthogonal groups, knots, and vortices
We consider Seiberg electric-magnetic dualities for 4d SYM
theories with SO(N) gauge group. For all such known theories we construct
superconformal indices (SCIs) in terms of elliptic hypergeometric integrals.
Equalities of these indices for dual theories lead both to proven earlier
special function identities and new conjectural relations for integrals. In
particular, we describe a number of new elliptic beta integrals associated with
the s-confining theories with the spinor matter fields. Reductions of some
dualities from SP(2N) to SO(2N) or SO(2N+1) gauge groups are described.
Interrelation of SCIs and the Witten anomaly is briefly discussed. Possible
applications of the elliptic hypergeometric integrals to a two-parameter
deformation of 2d conformal field theory and related matrix models are
indicated. Connections of the reduced SCIs with the state integrals of the knot
theory, generalized AGT duality for (3+3)d theories, and a 2d vortex partition
function are described.Comment: Latex, 58 pages; paper shortened, to appear in Commun. Math. Phy
Organic solvent-tolerant bacterium which secretes an organic solvent-stable proteolytic enzyme
Organic-Solvent-Tolerant Bacterium Which Secretes Organic-Solvent-Stable Lipolytic Enzyme
Novel sol-gel immobilization of horseradish peroxidase employing a detergentless micro-emulsion system
Facile preparation of biodegradable glycol chitosan hydrogels using divinyladipate as a crosslinker
Water Concentration and Activity Effects on Aminoacylase in Aqueous/Organic One-Liquid-Phase Systems
Kinetic mechanisms of cholesterol oxidase from Streptomyces hygroscopicus and Brevibacterium sterolicum
The kinetic properties of two cholesterol oxidases, one from Brevibacterium sterolicum (BCO) the other from Streptomyces hygroscopicus (SCO) were investigated. BCO works via a ping-pong mechanism, whereas the catalytic pathway of SCO is sequential. The turnover numbers at infinite cholesterol and oxygen concentrations are 202 sâ1 and 105 sâ1 for SCO and BCO, respectively. The rates of flavin reduction extrapolated to saturating substrate concentration, under anaerobic conditions, are 235 sâ1 for BCO and 232 sâ1 for SCO (in the presence of 1% Thesit and 10% 2-propanol). With reduced SCO the rate of Î5-6âÎ4-5 isomerization of the intermediate 5-cholesten-3-one to final product is slow (0.3 sâ1). With oxidized SCO and BCO the rate of isomerization is much faster (â 300 sâ1), thus it is not rate-limiting for catalysis. The kinetic behaviour of both reduced COs towards oxygen is unusual in that they exhibit apparent saturation with increasing oxygen concentrations (extrapolated rates â 250 sâ1 and 1.3 sâ1, for BCO and SCO, respectively): too slow to account for catalysis. For BCO the kinetic data are compatible with a step preceding the reaction with oxygen, involving interconversion of reactive and nonreactive forms of the enzyme. We suggest that the presence of micelles in the reaction medium, due to the necessary presence of detergents to solubilize the substrate, influence the availability or reactivity of oxygen towards the enzyme. The rate of re-oxidation of SCO in the presence of product is also too slow to account for catalysis, probably due to the impossibility of producing quantitatively the reduced enzyme product complexes
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