Direct observation of the enhancement of noncooperative protein self-assembly by macromolecular crowding: Indefinite linear self-association of bacterial cell division protein FtsZ

Recent measurements of sedimentation equilibrium and sedimentation velocity have shown that the bacterial cell division protein FtsZ self-associates to form indefinitely long rod-like linear aggregates in the presence of GDP and Mg2+. In the present study, the newly developed technique of non-ideal tracer sedimentation equilibrium was used to measure the effect of high concentrations—up to 150 g/liter—of each of two inert “crowder” proteins, cyanmethemoglobin or BSA, on the thermodynamic activity and state of association of dilute FtsZ under conditions inhibiting (−Mg2+) and promoting (+Mg2+) FtsZ self-association. Analysis of equilibrium gradients of both FtsZ and crowder proteins indicates that, under the conditions of the present experiment, FtsZ interacts with each of the two crowder proteins essentially entirely via steric repulsion, which may be accounted for quantitatively by a simple model in which hemoglobin, albumin, and monomeric FtsZ are modeled as effective spherical hard particles, and each oligomeric species of FtsZ is modeled as an effective hard spherocylinder. The functional dependence of the sedimentation of FtsZ on the concentrations of FtsZ and either crowder indicates that, in the presence of high concentrations of crowder, both the weight-average degree of FtsZ self-association and the range of FtsZ oligomer sizes present in significant abundance are increased substantially.

Refinery Nonconventional Feedstocks: Influence of the Coprocessing of Vacuum Gas Oil and Low Density Polyethylene in Fluid Catalytic Cracking Unit on Full Range Gasoline Composition

Gasoline coming from refinery fluid catalytic cracking (FCC) unit is a major contributor to the total commercial grade gasoline pool. The contents of the FCC gasoline are primarily paraffins, naphthenes, olefins, aromatics, and undesirables such as sulfur and sulfur containing compounds in low quantities. The proportions of these components in the FCC gasoline invariable determine its quality as well as the performance of the associated downstream units. The increasing demand for cleaner and lighter fuels significantly influences the need not only for novel processing technologies but also for alternative refinery and petrochemical feedstocks. Current and future clean gasoline requirements include increased isoparaffins contents, reduced olefin contents, reduced aromatics, reduced benzene, and reduced sulfur contents. The present study is aimed at investigating the effect of processing an unconventional refinery feedstock, composed of blend of vacuum gas oil (VGO) and low density polyethylene (LDPE) on FCC full range gasoline yields and compositional spectrum including its paraffins, isoparaffins, olefins, napthenes, and aromatics contents distribution within a range of operating variables of temperature (500–700 °C) and catalyst-feed oil ratio (CFR 5–10) using spent equilibrium FCC Y-zeolite based catalyst in a FCC pilot plant operated at the University of Alicante’s Research Institute of Chemical Process Engineering (RICPE). The coprocessing of the oil-polymer blend led to the production of gasoline with very similar yields and compositions as those obtained from the base oil, albeit, in some cases, the contribution of the feed polymer content as well as the processing variables on the gasoline compositional spectrum were appreciated. Carbon content analysis showed a higher fraction of the C9–C12 compounds at all catalyst rates employed and for both feedstocks. The gasoline’s paraffinicity, olefinicity, and degrees of branching of the paraffins and olefins were also affected in various degrees by the scale of operating severity. In the majority of the cases, the gasoline aromatics tended toward the decrease as the reactor temperature was increased. While the paraffins and iso-paraffins gasoline contents were relatively stable at around 5 % wt, the olefin contents on the other hand generally increased with increase in the FCC reactor temperature.

The scourging of a race : and other sermons and addresses /

Mode of access: Internet.

Quadrennial address of the bishops of the Colored Methodist Episcopal Church to the fourteenth session of the General Conference : held in Saint Louis, Missouri, May third, one thousand nine hundred and twenty two.

Signed at end: Isaac Lane (retired). Robert Simeon Williams. Elias Cottrell. Charles Henry Phillips. Randall Albert Carter. Nelson Caldwell Cleaves.

The Journal of Negro history [serial].

This title is in the TRLN Single Copy Archive. Electronic access also available.

The causes of illegitimacy particularly in Scotland /

"Being a paper read in Glasgow at the fourth annual meeting of the 'National association for the promotion of social science,' on the 28th of September 1860."

With the ears of strangers; the Mexican in American literature.

Rev. ed. (c1977) published under title: Mexico and the Hispanic Southwest in American literature.

The Crisis.

Editor: 1910- W.E.B. Du Bois.

Report of the Second Norwegian Arctic Expedition in the "Fram," 1898-1902.

Accompanied by supplementary volume (various pagings) issued in 1930.

The works of Edgar Allan Poe.

Tales of the grotesque and arabesque: I. Romances of death. Old-world romance.--II. Tales of conscience, natural beauty, and pseudo-science.--III. Tales of ratiocination and illusion.--IV. Extravaganza and caprice.--V. Tales of adventure and exploration.--Literary criticism: VI. On poetry and the poets.--VII. On novels, essays, and travels. Marginalia.--VIII. The literati. Minor contemporaries, etc.--IX. Eureka, and miscellanies.--X. Poems.--Bibliography (v. 10, p. 273-309)

The works of Edgar Allan Poe : newly collected and edited, with a memoir, critical introductions, and notes /

Includes index.

Literary shrines; the haunts of some famous American authors,

Mode of access: Internet.

Leading American cases and notes upon the law of wills : embracing testamentary capacity, undue influence, the admission of oral testimony in aid of the construction of wills, the execution of wills, &c. /

"A supplement to the author's work on wills, and arranged in a similar manner." --T.p.

Sermons by the Rev. Thomas Bacon, of Maryland, first published in 1763, on the duties of servants.

"Reprinted for the 'Society for the Advancement of Christianity in South-Carolina'."

The mind of the Negro as reflected in letters written during the crisis, 1800-1860,

Includes letters from Frederick Douglass.