Defining the membrane proteome of NK cells

The present study was initiated to define the composition of the membrane proteome of the Natural Killer (NK) like cell line YTS. Isolated membranes were treated with reagents that have been reported to remove peripheral membrane proteins. Additional steps involving trifluoroethanol (TFE) were introduced in an effort to remove remaining nonintegral membrane proteins. This treatment resulted in the release of a subset of proteins without any apparent disruption of membrane integrity. The membranes were solubilized and digested with trypsin in 25% TFE. The resulting peptides were separated using an off‐line two‐dimensional reversed phase LC technique at alkaline and acidic pHs. Mass spectrometric analysis identified 1843 proteins with high confidence scores. On the basis of the presence of transmembrane regions or evidence of posttranslational modifications and prediction algorithms, approximately 40% of the identified proteins were predicted as plausible membrane proteins. The remaining species were largely involved in cellular processes and molecular functions that could be predicted to be transiently associated with membranes. The analytical approaches presented in this study offer robust generic methods for the identification and characterization of membrane proteins. These observations highlight the fact that the membrane is a dynamic entity that is composed of integral and stably associated proteins. Copyright © 2009 John Wiley & Sons, Ltd.     

Comparison of "polynaphthalenes" prepared by two mechanistically distinct routes

The Bergman cyclization has long been known to produce polymers as side products. More recently, this attribute has been harnessed for the production of conjugated materials. However, the structures of these polymers have not been established. To resolve this question, the metal-catalyzed polymerization of 1,4-dibromonaphthalene and thermal polymerization of o-diethynylbenzene were conducted. Two distinct polymers were obtained. Comparison of IR spectroscopy, MALDI-TOF MS, solid-state NMR spectroscopy, UV-vis reflectance spectroscopy, and pyrolysis GC-MS data indicates that only one of the polymers is consistent with poly(1,4-naphthalene).     

Application of the intramolecular vinylogous Morita-Baylis-Hillman reaction toward the synthesis of the spinosyn A tricyclic nucleus

[reaction: see text] A concise synthesis of the spinosyn A tricyclic nucleus 27 has been developed by a route featuring a one-pot tandem intramolecular Diels-Alder reaction and intramolecular vinylogous Morita-Baylis-Hillman cyclization in which five stereocenters in tricycle 10 are set with excellent selectivity.     

Primal decomposition in rings, modules and lattice modules

In a work by L. Fuchs, W. Heinzer and B. Olberding, a decomposition of ideals in a commutative ring as intersections of primal isolated component ideals is investigated. In subsequent work by L. Fuchs and R. Reis, these ideas are developed in multiplicative lattices. The object of this note is to point out that, when specialized to the lattice of ideals of a commutative ring, the decomposition of L. Fuchs and R. Reis does not give the decomposition obtained in the paper by Fuchs, Heinzer and Olberding, and to give two variations of the decomposition of Fuchs and Reis. One of these variations, when specialized to the lattice of ideals of a ring, does give the decomposition obtained by Fuchs, Heinzer and Olberding, and the other one gives a decomposition which is superior in some ways. Received December 2, 2004; accepted in final form February 17, 2005.     

Solution‐Processable Donor–Acceptor Polymers with Modular Electronic Properties and Very Narrow Bandgaps

Bridgehead imine‐substituted cyclopentadithiophene structural units, in combination with highly electronegative acceptors that exhibit progressively delocalized π‐systems, afford donor–acceptor (DA) conjugated polymers with broad absorption profiles that span technologically relevant wavelength (λ) ranges from 0.7 < λ < 3.2 μm. A joint theoretical and experimental study demonstrates that the presence of the cross‐conjugated substituent at the donor bridgehead position results in the capability to fine‐tune structural and electronic properties so as to achieve very narrow optical bandgaps (E_g^opt < 0.5 eV). This strategy affords modular DA copolymers with broad‐ and long‐wavelength light absorption in the infrared and materials with some of the narrowest bandgaps reported to date.