Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Visible absorption, circular dichroism (CD) and magnetic circular dichroism spectra have been recorded for the Ca2+-Co2+ derivatives of the lentil (CCoLcH) and pea (CCoPSA) lectins (Co2+ at the S1 sites and Ca2+ at the S2 sites) and shown to be very similar for both proteins. The visible absorption and magnetic circular dichroism spectra indicate similar octahedral geometries for high spin Co2+ at S1 in both proteins, as found in the Ca2+-Co2+ complex of concanavalin A (CCoPL) (Richardson, C. E., and Behnke, W. D. (1976) J. Mol. Biol. 102, 441-451). The visible CD data, however, indicate differences in the environment around S1 of CCoLcH and CCoPSA compared to CCoPL. 1H NMR spectra at 90 MHz of the Co2+ and Ni2+ derivatives of the lectins show a number of isotropically shifted signals which arise from protons in the immediate vicinity of the S1 sites. Analysis of the spectra of the Co2+ derivatives in H2O and D2O has permitted resonance assignments of the side chain ring protons of the coordinated histidine at S1 in the lectins. Differences are observed in the H-D exchange rate of the histidine NH proton at S1 in concanavalin A compared to the lentil and pea lectins. NMR data of the Ni2+-substituted proteins, together with spectra of the Co2+ derivatives, also indicate that the side chains of a carboxylate ligand and of the histidine residue at S1 are positioned differently in concanavalin A than in the other two lectins. These results appear to account, in part, for the differences observed in the visible CD spectra of the Co2+-substituted proteins. In addition, binding of monosaccharides does not significantly perturb the spectra of the lectins. An unusual feature in the 1H NMR spectra of all three Co2+-substituted lectins is the presence of two exchangeable downfield shifted resonances which appear to be associated with the two protons of a slowly exchanging water molecule coordinated to the Ca2+ ion at S2. T1 measurements of CCoLcH have provided an estimation of the distances from the Co2+ ion to these two protons of 3.7 and 4.0 A.
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PMID:Circular dichroism and 1H NMR studies of Co2+- and Ni2+-substituted concanavalin A and the lentil and pea lectins. 368 Feb 86

Reversible linking of proteins with Cu2+ and Ni2+ ions was used to study the topography of the structural proteins of bacteriophage T4 basal plate. Gene products (GP) 9 and 10 were found to directly contact the proximal part of long fibrils (GP34). GP27, GP54 and GP5 interact with the lower disk of the contractive sheath (GP18), while GP48 and GP54 are in contact with the core (GP19). The proteins of the sheath (GP18) and the core (GP19) were found to have contact over the whole tail length.
Mol Biol (Mosk)
PMID:[Proteins of the basal plate of bacteriophage T4 participating in the contractile impulse]. 387 56

Experiments in isolated left auricle and right ventricular papillary muscle from guinea-pig hearts were performed in order to study the effects of nickel ions (Ni2+) on the transmembrane action potential. On the electrically paced guinea-pig left auricle NiCl2 in 10(-8)M concentration did not modify the action potential (AP). 10(-7)M Ni2+ caused a slight hyperpolarizing effect, markedly enhanced the maximum rate of rise of AP (Vmax) and shortened the duration of AP.10(-6) and 10(-5)M NiCl2 dose-dependently accelerated the repolarization, while 10(-5)M had a strong depolarizing effect, too. The stimulatory effect of 10(-7)M NiCl2 on Vmax could be observed under Ca-free condition too. Increase of Vmax caused by 10(-7)M Ni2+ was not prevented by cholinergic blockade (atropine, 3 X 10(-7)M) by beta-adrenergic blockade (pindolol, 4 X 10(-7)M) or by inhibition of prostaglandin synthesis (indomethacin, 10(-6)M). On the electrically paced guinea-pig papillary muscle both 10(-7)M and 10(-5)M NiCl2 increased the resting membrane potential (RP), the overshoot and Vmax but accelerated only slightly the initial repolarization phase. A concentration of 10(-4)M NiCl2, however, without causing any effect on the other parameters, shortened the whole repolarization phase. The h infinity-curve relating Vmax of the ventricular action potential to the membrane potential was increased by 10(-7)M Ni2+. The increase of Vmax was more pronounced at membrane potentials more negative than -75 mV and could not be observed at membrane potentials more positive than -70 mV. Steady state inactivation of Vmax was shifted by 5 mV to more negative potentials by 10(-7)M Ni2+.(ABSTRACT TRUNCATED AT 250 WORDS)
J Mol Cell Cardiol 1985 May
PMID:Effects of nickel ions on the transmembrane action potential of guinea-pig heart preparations. 403 85

The results of recent histopathologic studies of the nasal mucosa in nickel workers show that, in addition to metaplastic changes, there are frequently dysplastic alterations which are probably preneoplastic lesions. Seen by scanning electron microscopy metaplasia appears monomorphic and no major qualitative differences exist between nickel workers and controls of the same age although it tends to be more pronounced in the former group. Dysplasia and carcinoma, on the other hand, are characterized by considerable polymorphism in surface features which make distinction from metaplasia simple. In both dysplasia and carcinoma four defined types of surface can be distinguished: globule- and tongue-like structures, pleomorphic microvilli and microridges. In addition, parts of individual cells and adjacent cells often show a considerable variation in surface pattern. The surface structures are dynamic features and changes in these are related to the degree of maturation, genetic and metabolic properties of epithelial cells.
Virchows Arch B Cell Pathol Incl Mol Pathol 1982
PMID:The surface structure of the human nasal mucosa. II. Metaplasia, dysplasia and carcinoma in nickel workers. A correlated study by scanning/transmission electron and light microscopy. 612 31

This study presents a simple morphometric method for objective classification of pseudostratified, various types of metaplastic, and dysplastic epithelium by evaluation of cellular features in the basal layer only. Fifty-four biopsy specimens were taken for diagnostic reasons from the nasal mucosa of nickel workers, and semithin toluidine-blue-stained sections were analysed. The most sensitive parameters in distinguishing between the various types of epithelium were: (i) the transverse nuclear diameter, (ii) the size of the nucleoli and (iii) the basal cell width expressed as an index weighted towards the cell profiles with the broadest attachment face on the basal lamina. A combination of these three parameters allows a clear separation between dysplastic, metaplastic and pseudostratified epithelium. The sequential increase in these parameters from pseudostratified epithelium through two histologically distinguishable stages of metaplasia (stratified cuboidal and mixed stratified cuboidal/stratified squamous epithelium) to fully developed squamous epithelium supports the concept that metaplasia develops gradually. The continuous increase in these parameters from metaplasia to dysplasia further suggests that metaplasia is a necessary step in the development of nasal epithelial dysplasia. This morphometric model appears especially useful in monitoring small sequential epithelial changes, and might also be used for evaluating other types of epithelia.
Virchows Arch B Cell Pathol Incl Mol Pathol 1983
PMID:Discrimination of various epithelia by simple morphometric evaluation of the basal cell layer. A light microscopic analysis of pseudostratified, metaplastic and dysplastic nasal epithelium in nickel workers. 613 90

With the use of the strain-overproducer restriction endonuclease R.EcoRV was isolated and purified to homogeneity. The molecular mass of the enzyme was determined by gel filtration and polyacrylamide gel electrophoresis to be 25 000 daltons. According to the data of immunological tests R.EcoRV differs in its antigenic characteristics from restriction endonucleases R.EcoRI and R.EcoRII. Dependence of enzyme activity on pH, ionic strength, temperature, presence of divalent cations (Mn2+, Mg2+, Co2+, Zn2+, Ni2+ and Cd2+) and organic solvents (glycerol, dimethylsulfoxide, ethanol) has been studied. It was shown that under conditions of replacement of Mg2+ for Mn2+ or after addition of organic solvents relaxation of R.EcoRV specificity takes place. It was shown also that R.EcoRV is able to digest T-even bacteriophage DNAs with different types and extents of modification. DNA modified by the action of MR.EcoRV system in vivo is susceptible to R.EcoRV in vitro. Under conditions of relaxed specificity noncanonical sites are susceptible to R.EcoRV attack. The fragments resulted may be cloned in canonical pBR322 EcoRV site.
Mol Biol (Mosk)
PMID:[EcoRV restrictase: physical and catalytic properties of homogenous enzyme]. 620 Jul 65

The Ca2+-dependent ATPase was solubilized from rat heart sarcolemmal membranes upon digestion with trypsin and was found to be different from Ca2+-stimulated Mg2+-dependent ATPase (Dhalla, N. S., Anand-Srivastava, M. B., Tuana, B. S., and Khandelwal, R. L. (1981) J. Mol. Cell. Cardiol. 13, 413-423). The enzyme was purified by high speed centrifugation, ammonium sulfate fractionation, and column chromatography and was seen as a single protein band in nondenaturing polyacrylamide gel electrophoresis. In sodium dodecyl sulfate-acrylamide gels, the enzyme dissociated into two subunits or fragments with molecular weights of about 55,000 and 12,000. The molecular weight of the enzyme, estimated by gel filtration on a Sephadex G-100 column, was found to be about 67,000. The enzyme utilized ATP with a Km of 0.20-0.26 mM but was also able to utilize ITP, CTP, GTP, and ADP as substrates at much lower rates. It was activated by Ca2+ with a Ka of 0.13-0.21 mM; it was also activated by other cations in the order Ca2+ greater than Mn2+ greater than Sr2+ greater than Ba2+ greater than Mg2+. Divalent cations like Cu2+, Ni2+, and Mg2+ were potent inhibitors. The enzyme was insensitive to ouabain, verapamil, oligomycin, cyanide, and vanadate but was markedly inhibited by N-ethylmaleimide. Calmodulin failed to stimulate Ca2+-dependent ATPase and instead inhibited slightly. Unlike K+, Na+ produced a marked inhibition of the Ca2+-dependent ATPase activity, and this inhibition was associated with an 8- 10-fold decrease in the affinity of the enzyme for Ca2+. The competitive action of Na+ indicates that the Ca2+-dependent ATPase may be a site of Na+-Ca2+ antagonism in the cell membrane.
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PMID:Purification and characterization of a Ca2+-dependent ATPase from rat heart sarcolemma. 621 55

A new method of estimation of the distance RLM between the nitroxide spin label (NSL) and the paramagnetic metal ions (PMI), such as Co2+, Ni2+, Cu2+, Mn2+, VO2+, Cr3+, Fe3+ is suggested. The influence of the longitudinal relaxation time T1 of the PMI on the line shape of the NSL at 77 degrees K has been studied. It was found that the efficiency of the dipole-dipole interaction between NSL and PMI depends strongly on the T1 value of the PMI. Measurements of the RLM for 4 spin-labelled proteins (haemoglobin, nitrogenase, cytochrome P450 and Ca2+-dependent ATPase) by three various methods have proved the correctness of the new method and also its simplicity.
Mol Biol (Mosk)
PMID:[New method for measuring the distances between the nitroxide spin label and paramagnetic metal ions in macromolecules]. 626 67

The interactions of Ni(II) cation with a representative suite of purine bases and the respective nucleosides and nucleotides have been studied by ultraviolet difference spectroscopy. Apparent association constants, Kapp, were determined for each system at pH 7.0, using computer linear regression coupled with an iteration technique. The specificity of binding of Ni2+ for the purine nucleotides studied at pH 7.0 was 5'-GMP greater than 5'-IMP greater than 5'-AMP; a similar ordering was also found for the respective nucleosides and bases. In this study binding was not observed for the suite of pyramidines used, although a Ni2+ - cytidine complex has been observed (Fiskin and Beer, 1965). It was also found that Ni2+ bound more strongly to the purine 5'-nucleotides than to the respective nucleosides and bases. These trends are explained in terms of metal-ligand bonds and available bonding positions on the ligands. A role for metal-ion-nucleotide types of complexes is suggested in the processes that might have given rise to the origin of life.
J Mol Evol 1982
PMID:Binding of nickel (II) to 5'-nucleoside monophosphates and related compounds. 628 47

1. Spontaneous transmitter release was studied at the frog sartorius neuromuscular junction in the presence of a variety of cations before and after treatment with the specific presynaptic neurotoxin, beta-bungarotoxin (beta-BuTX). 2. Treatment with beta-BuTX produced a maintained increase in spontaneous release, as indicated by the miniature end-plate potential (m.e.p.p.) frequency. It was demonstrated that the m.e.p.p. frequency remained dependent on the extracellular calcium concentration. 3. A 30 mM increase in extracellular sodium chloride produced a reversible increase in frequency only after beta-BuTX treatment, indicating that beta-BuTX had increased the permeability of the presynaptic terminal. 4. Furthermore, several divalent cations other than calcium were shown to either maintain or greatly increase the m.e.p.p. frequency after beta-BuTX treatment (before toxin treatment replacement of calcium by these divalent cations produced only small changes in frequency). The relative effectiveness of the divalent cations tested in increasing spontaneous transmitter release after toxin treatment was Co2+ congruent to Ni2+ greater than Mg2+ greater than Ca2+ congruent to Sr2+ greater than Mn2+. The effect of cobalt, which increased the m.e.p.p. frequency 6.5 times after toxin treatment, was studied in detail.
Cell Mol Neurobiol 1982 Dec
PMID:Alterations in spontaneous transmitter release by divalent cations after treatment of the neuromuscular junction with beta-bungarotoxin. 630 1


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