Surface and solvent influences on protein crystallization

The role of water in protein crystallization was explored by investigating the effects of three factors (salts, point mutations and pressure) on subtilisin crystallization.;Solubility and growth kinetics of three subtilisin mutants in three salt solutions were measured. The decrease of the solubility of Properase RTM and PurafectRTM subtilisin followed the reverse order of the Hofmeister series: SCN- \u3e NO3- \u3e Cl-. The solubility of ProperaseRTM was higher than other two mutants. Crystal morphology changed with the nature of salts and the substitution of surface residues. The required supersaturation (c-s)/s for a given growth rate increased when solubility was decreased. The effect of anion on protein growth was related to the molar Gibbs free energy of hydration of the anion.;Structural and energetic considerations for crystallization of two subtilisin mutants (ProperaseRTM and PurafectRTM) were compared. The average hydrophobicity, solvent accessible surface area (ASA) and the number of hydrogen bonds and salt bridges were calculated to quantify surface properties of proteins in intermolecular contact patches. All three amino acid substitutions are present in the contact patches. Properase RTM lattice involves more atomic contacts and hydrogen bonds and larger accessible surface area, which corresponding to the faster growth of ProperaseRTM crystals. Non-electrostatic interaction energy was calculated for each contact direction and the competition of misoriented molecules with correctly oriented ones was considered to explain the variation of growth kinetics;The increase of solubility with pressure gave a total volume change for crystallization of 37 cm3/mol, whereas the decrease of nucleation rate with pressure gave an activation volume for nucleation of 226 cm 3/mol. 983 water molecules were estimated to attend Properase RTM crystallization.;The second virial coefficients (B2) of Properase RTM and PurafectRTM subtilisin under crystallization conditions were measured by static light scattering as a function of salt type and salt concentration, showing that conditions with slight negative B2 are suitable for protein crystallization. A DLVO-type model was used to fit the effective Hamaker constants for subtilisin and solubility was quantitatively correlated with B2 using a theoretically based correlation

The Grizzly, November 13, 1990

Clergy Assembly Meets Ninth Consecutive Year • Career Day: An Information Session for Students • U.S. Energy Policy Anti-American? • The Ursinus Tutoring Program • Being British Without Being English • Election Results • Students React to Reimert Security Doors • Greeks Sponsor Halloween Party • F.W. Olin Foundation • Wilk 3 Protest • The History of Olin Grant • The Changeling • INXS • Television: Whose Reality is it Anyway? • Swimmers Wash Out Washington • Cross-Country Team Pleased with Regionals • Steimy Starts Club • Men\u27s Basketball Looks for Improvement in 1991 Season • Football Finishes Season with a Loss • Letters: No Defense for Personal Abuse; Zeta Chi Missed the Point! • Uncle Sam Wants Everyone • Pre-Med Prognosis Improving • Ursinus Grad in Sticky Situation • Brownback-Anders Meetinghttps://digitalcommons.ursinus.edu/grizzlynews/1264/thumbnail.jp

Mesilla Valley Independent, 06-22-1878

Contains Spanish language content as El Independiente del Valle de la Mesilla ; DISC drive NDNP-01, Gilahttps://digitalrepository.unm.edu/mvi_news/1038/thumbnail.jp

Diagenesis of sandstones from the Douglas Creek member of the Green River Formation (Eocene) at Red Wash field, Uintay County, Utah

Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to [email protected], referencing the URI of the item.Bibliography: leaves 80-82.Not availabl

The Determinants of Mergers and Acquisitions in the Oil & Gas Industry: Evidence from Canadian and American Transactions

The study investigates the determinants of mergers and acquisitions in the oil and gas industry over the ten-year period from 2002 to 2011. Our large sample analysis results indicate that in the O&G industry: (1) U.S. acquirers are larger than Canadian acquirers overall; (2) value bidders generate greater abnormal returns relative to glamour bidders in Canadian market; (3) the geographical proximity of headquarters cannot generate pronounced synergies, and even destroys penny stock bidder’s value; and (4) there is no mispricing effect in the penny stocks, but they are more illiquid and have a higher level of idiosyncratic risk. We also examine three cases in 2012-2013 to verify our results and to identify several firm specific factors that are not considered in the large sample analysis. Consistent with our expectations, the Canadian transaction is more straightforward whereas the U.S. transactions depend more on pre-existing connections between the firms and suggest more corporate governance concerns