No abstract

By using a method that labels sulfhydryl-containing proteins in situ, we (6,14,15). It reacts selectively with the thiol anion of sulfhydryls, crosses biological membranes, and does not significantly alter the molecular weight of proteins (6,14,15).We have used mB to label the sulfhydryl-containing proteins of the outer membrane of Neissena gonorrhoeae. By labeling during growth, we have eliminated the effect of oxidative changes that occur during harvesting and preparation of fractions, thereby detecting the sulfhydryl status of proteins in situ.A nonpiliated, opaque colonial variant of N. gonorrhoeae 1384 (22, 23) was used for all studies. Growth conditions were as previously described (23) (Pharmacia, Piscataway, N.J.) with 0.9 mM dithiothreitol for 30 min and 5.4 mM mB for 20 min. The treated standards were diluted into sample buffer with mercaptoethanol (ME).Electrophoretic analysis of outer membranes from labeled samples revealed multiple fluorescent bands, with the two major fluorescent bands having apparent molecular masses of 41 and 31.5 kDa (Fig. 1A and B). On the basis of its intense fluorescence, the protein at 41 kDa is the major sulfhydryl-containing protein in the outer membrane. Gels stained for protein also showed the 41-kDa protein to be a major protein band in labeled fractions (Fig. 1D, lanes 3 and 5), with an intensity equivalent to that of PIII as seen in outer membrane fractions prepared by conventional methods. However, unlabeled fractions that were not reduced by ME showed no evidence of this protein (Fig. 1D, lanes 1 and 4). When unlabeled samples were reduced, only a lightly staining protein band at 41 kDa was seen (Fig. 1C, lanes 1 and 4). Samples obtained from different experiments (Fig. 1, lanes 1 to 3 versus lanes 4 and 5) confirmed the differences in the 41-kDa protein between labeled and unlabeled samples. Although there was some variation in the intensity of the 41-kDa protein between the two unlabeled, reduced samples, in both cases there was significantly less protein than in labeled samples.There are several possible reasons for the difference between the labeled and unlabeled samples. A likely explanation, given the nature of sulfhydryl compounds, the nature of the reaction with mB, and the effect of ME on the 41-kDa protein in the unlabeled samples, is that in the unlabeled samples artifacts of distribution occur during preparation of the fractions and result in decreases of the 41-kDa protein in the outer membrane; i.e., the protein undergoes autoxidation, with a change in conformation and loss from the membrane, whereas in labeled samples the 41-kDa protein is stable because of its reaction with mB. Another possibility is

This paper brings together C * -algebras and algebraic topology in terms of viewing a C * -algebraic invariant in terms of a topological spectrum. E-theory, E(A, B), is a bivariant functor in the sense that is a cohomology functor in the first variable and a homology functor in the second variable but underlying goes from the category of separable C * -algebras and * -homomorphisms to the category of abelian groups and group homomorphisms. Here we create a generalisation of a orthogonal spectrum to quasi-topological spaces for E-theory . This includes a rich product structure in the context of graded separable C * -algebras.

We produce an explicit description of the K-theory and K-homology of the pure braid group on n strands. We describe the Baum-Connes correspondence between the generators of the left-and right-hand sides for n = 4. Using functoriality of the assembly map and direct computations, we recover Oyono-Oyono's result on the Baum-Connes conjecture for pure braid groups [OO01]. We also discuss the case of the full braid group B3.

We give a proof of Bott periodicity for real graded C * -algebras in terms of Ktheory and E-theory. Guentner and Higson [9] proved a similar result in the complex graded case but we extend this to cover all graded C * -algebras. We obtain the 8-fold periodicity in E-theory by constructing two maps that are inverse to each other.Theorem A. For a finite dimensional Euclidean vector space V over R, the Bott map induces the isomorphism of K-theoryIn order to prove this, we construct an inverse map α t to β,and we will show that the induced composition α * β * is equivalent to a simpler map γ t : S → K(H(V )). The map γ t will give a K-theory equivalence. Additionally we use the Atiyah rotation trick [2] to prove β * α * yields the identity in K-theory. We will obtain the following Corollary and Theorem by showing that when V = R then C 0 (V, Cliff(V )) = ΣR ⊗R 1,0 : 1 Corollary. We have an isomorphism K(R) ∼ = K(ΣR ⊗R 1,0 ).Theorem B. For a real graded C * -algebra A, we have a natural isomorphism K(A) ∼ = K(ΣA ⊗R 1,0 ).Finally we will transfer this into E-theory by using the relation between K-and E-theory, namely K(A) := E(R, A), and obtain Theorem C. For real graded C * -algebras A and B, E(A, B) ∼ = E(A, ΣB ⊗R 1,0 ).This result will be obtained by the tensor product bifunctor property of E-theory and the facts that both β and α t give classes in E-theory which are invertible. Then we use properties of Clifford algebras to formulate the 8-fold periodicity in E-theory.1. the map t → ϕ t (a), from [1, ∞) to B is continuous and bounded for each a ∈ A,