Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0847097 (acidity)
 15,165 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Semi-dominant mutations in the amdA gene lead to elevated expression of the gene encoding acetamidase, amdS. These mutations also cause constitutive expression of the acetate-inducible gene, aciA. In the amdS 5' regulatory region, two cis-acting mutations, amdl66 and amdl666, have been isolated which specifically affect amdA activation of amdS. These mutations are a duplication and a triplication of an 18 bp GA-rich sequence, thought to define the amdA site of action within the amdS promoter region. Similar GA-rich sequences have also been found in the 5' region of aciA. This paper describes the cloning and initial functional characterization of the amdA gene and two of its mutant alleles. The wild-type amdA gene has been cloned by a chromosome walk from genes gatA and alcC on linkage group VII and localized by complementation of an amdA loss-of-function mutation. Transcriptional analysis reveals that the gene is expressed constitutively at low levels under growth conditions which affect expression of amdS and aciA. The gene is predicted to encode an 880-amino-acid protein which contains two C2H2 zinc fingers, a nuclear localization sequence and two transcriptional activation domains. The amdA7 semi-dominant gain-of-function mutation results in a glycine to aspartate substitution which would increase the acidity of one of these regions. Analysis of in vitro generated mutations in the 5' region of amdS using an amdS::lacZ reporter has been used to localize the site of action of AmdA. The C2H2 zinc-finger motifs identified in the protein are similar to those found in the carbon catabolite repressor protein, CreA, which also regulates amdS and recognizes sequences which overlap with the proposed site of action for AmdA.
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PMID:The positively acting amdA gene of Aspergillus nidulans encodes a protein with two C2H2 zinc-finger motifs. 759 97

In this paper, two methods of N2O/C2H2 FAAS and FAES are applied to determine aluminium in healthman hair. The requirement of determination, interferences of inorganic ions and organic substances and the results of determination are contrasted respectively. It is shown experimently that the interference ratio of substances, accuracy, sensitivity and recovery ratio of FAES are superior to FAAS at 396.1 nm wavelength in acidity medium. The RSD (n = 9) of FAES and FAAS are 2.2 and 2.7% respectively and detect limit is 0.07 microg/mL for FAES and 0.25 microg/mL for FAAS. The recovery ratio of adding 20.0 microg aluminium to 1.0 g hair samples are 96.5-105.0% and 93.5-106.5% respectively.
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PMID:[Determination of aluminium in healthy person's hair by FAAS and FAES]. 1581 Mar 44

Arsenic is a biologically interesting element with both antitumor and carcinogenic effects. Zinc finger proteins (ZFPs) have been confirmed to be the cellular targets of arsenite; however, arsenite inhibits ZFPs much less efficiently in vitro than in vivo. The molecular mechanism of this difference is unknown. In this work, we found that the reaction of arsenite with ZFPs relies on the presence of small biomolecules such as glutathione (GSH), histidine, and cysteine (Cys). The weak acidity also enhances the reaction. Further study shows that the coordination of zinc is much more susceptible than that of arsenic to these solution conditions, which enhance the competition of arsenic. Notably, different from C3H-type ZFPs, the C2H2-type ZFPs are more significantly influenced by the presence of thiol-containing molecules in the reaction. GSH and Cys can facilitate the reaction by participation of the coordination to As(III) together with C2H2-type ZFPs. Consequently, the reactions are promoted both thermodynamically and kinetically via the formation of ternary complexes GSH-As-ZFP or Cys-As-ZFP. These results indicate that the reactions between arsenite and proteins are considerably modulated by environments such as the small biomolecules and the acidity of the solution. This finding clarifies the discrepancy observed in the reactions of arsenite in vitro versus in cells, and provides an insight into the molecular mechanism of arsenite.
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PMID:The reaction of arsenite with proteins relies on solution conditions. 2460 49