In Streptococcus lactis ML3 and Streptococcus cremoris Wg2 the uptake of glutamate and glutamine is mediated by the same transport system, which has a 30-fold higher affinity for glutamine than for glutamate at pH 6.0. The apparent affinity constant for transport (KT) of glutamine is 2.5 +/- 0.3 microM, independent of the extracellular pH. The KTS for glutamate uptake are 3.5, 11.2, 77, and 120...

Binding of Mn(pi)-nucleotide complexes to the enzyme formyltertrahydrofolate synthetase (EC 6.3.4.3) from Clostridium cylindrosporum has been examined in the presence and absence of other substrates by solvent proton relaxation mearurements. MnADP and MnATP form ternary complexes with the enzyme with highly enhanced proton relaxation rates for water. The enhancement parameters, epsilont, for th...

sulfonated poly (ether ether ketone) (speek) with a low degree of sulfonation (ds = 40%) was prepared for proton exchange membrane fuel cells (pemfc). poly (ether ether ketone) (peek) was sulfonated in concentrated h2so4 under n2 atmosphere and characterized by the hydrogen nuclear magnetic resonance (h-nmr) technique. after preparation of the speek polymer, the obtained polymer was dissolved i...

proton exchange membrane fuel cells (pemfcs) are electrochemical devices that show the highest power densities compared to the other type of fuel cell. in this work, nanocomposite membranes used for proton exchange membrane fuel cells as poly(vinyl alcohol)/la2ce2o7 (pva-lc) with the aim of increasing the water uptake and proton conductivity. glutaraldehyde (ga) was used as cross linking agent ...

We have analyzed the structure and bonding of gas-phase Cl-X and [HCl-X](+) complexes for X(+)= H(+), CH3 (+), Li(+), and Na(+), using relativistic density functional theory (DFT). We wish to establish a quantitative trend in affinities of the anionic and neutral Lewis bases Cl(-) and HCl for the various cations. The Cl-X bond becomes longer and weaker along X(+) = H(+), CH3 (+), Li(+), and Na(...

in this study we produced and purified a high titer of specific and high affin¬ity fab fragments of anti-digoxin antibody. immunization of rabbits with a conju¬gate of the cardiac glycoside digoxin, coupled by a periodate oxidation method to the amino group of lysine in bovine serum albumin resulted in the production of this type of high titer digoxin-specific antibodies with exceptionally high...

two sialic acid specific lectins episesarma tetragonum agglutinin–1 and 2 were purified from the hemolymph of the mangrove crab, episesarma tetragonum . the major lectin was purified using cnbr-activated sepharose 4b conjugated to fetuin. n-acetyl glucosamine containing buffer was used for elution. the hemagglutination activity of purified lectin was inhibited by glycoproteins containing siaα, ...