Cation Bridge
Mostrando 1-9 de 9 artigos, teses e dissertações.
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1. Compartimentos da matéria orgânica do solo, agregação, mecanismos de proteção e sequestro de carbono influenciados pela calagem superficial em sistema plantio direto
A calagem é a prática mais utilizada para neutralizar a acidez do solo, porém promove também modificações químicas capazes de alterar os compartimentos da matéria orgânica do solo (MOS) e mecanismos de floculação, formação e estabilização de macro e microagregados. O objetivo desse trabalho foi avaliar o seqüestro de carbono, na amostra integ
Publicado em: 2010
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2. Altered kinetics of contraction in skeletal muscle fibers containing a mutant myosin regulatory light chain with reduced divalent cation binding.
We examined the kinetic properties of rabbit skinned skeletal muscle fibers in which the endogenous myosin regulatory light chain (RLC) was partially replaced with a mutant RLC (D47A) containing a point mutation within the Ca2+/Mg2+ binding site that severely reduced its affinity for divalent cations. We found that when approximately 50% of the endogenous RL
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3. Probing alkali metal–π interactions with the side chain residue of tryptophan
Feeble forces play a significant role in the organization of proteins. These include hydrogen bonding, hydrophobic interactions, salt bridge formation, and steric interactions. The alkali metal cation-π interaction is a force of potentially profound importance but its consideration in biology has been limited by the lack of experimental evidence. Our previo
National Academy of Sciences.
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4. Calcium-like Action of Phenethylbiguanide and Related Compounds: Inhibition of Pyruvate Kinase
Pyruvate kinase (EC 2.7.1.40) is inhibited by phenethylbiguanide. The kinetics of inhibition are competitive between biguanide and divalent, but not monovalent, metal cation activators of the enzyme; biguanide inhibition thus resembles inhibition by Ca++. Alteration of either the polar or nonpolar portion of the phenethylbiguanide molecule quantitatively red
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5. Poplar Metal Tolerance Protein 1 Confers Zinc Tolerance and Is an Oligomeric Vacuolar Zinc Transporter with an Essential Leucine Zipper Motif
Cation diffusion facilitator (CDF) proteins are a recently discovered family of cation efflux transporters that might play an essential role in metal homeostasis and tolerance. Here, we describe the identification, characterization, and localization of PtdMTP1, a member of the CDF family from the hybrid poplar Populus trichocarpa × Populus deltoides. PtdMTP
American Society of Plant Biologists.
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6. Mechanism of Action of Bacitracin: Complexation with Metal Ion and C55-Isoprenyl Pyrophosphate
The inhibition by bacitracin of the enzymatic dephosphorylation of C55-isoprenyl pyrophosphate is abolished by the addition of chelating agents. If, however, the chelating agent is added after a preincubation of bacitracin with a divalent cation and the lipid substrate, then its addition has little effect, indicating that bacitracin, metal ion, and C55-isopr
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7. Mechanism of action of endothelin in rat cardiac muscle: cross-bridge kinetics and myosin light chain phosphorylation.
1. The molecular mechanism of inotropic action of endothelin was investigated in rat ventricular muscle by studying its effects on characteristics of isometric twitch, barium-induced steady contracture and the level of incorporation of 32Pi into myosin light chain 2. 2. Exposure of rat papillary muscle to endothelin caused an increase in isometric twitch for
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8. Crystal structure and characterization of a cytochrome c peroxidase–cytochrome c site-specific cross-link
A specific covalently cross-linked complex between redox partners yeast cytochrome c peroxidase (CCP) and cytochrome c (cyt. c) has been made by engineering cysteines into CCP and cyt. c that form an intermolecular disulfide bond in high yield. The crystal structure of the cross-linked complex has been solved to 1.88-Å resolution and closely resembles the s
National Academy of Sciences.
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9. Arg-52 in the Melibiose Carrier of Escherichia coli Is Important for Cation-Coupled Sugar Transport and Participates in an Intrahelical Salt Bridge
Arg-52 of the Escherichia coli melibiose carrier was replaced by Ser (R52S), Gln (R52Q), or Val (R52V). While the level of carrier in the membrane for each mutant remained similar to that for the wild type, analysis of melibiose transport showed an uncoupling of proton cotransport and a drastic reduction in Na+-coupled transport. Second-site revertants were
American Society for Microbiology.