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Identification of a single nucleotide change in a mutant gene for hypoxanthine-guanine phosphoribosyltransferase (HPRTAnn Arbor) 总被引:1,自引:1,他引:0
Shin Fujimori Yuji Hidaka Beverly L. Davidson Thomas D. Palella William N. Kelley 《Human genetics》1988,79(1):39-43
Summary HPRTAnn Arbor is a variant of hypoxanthine (guanine) phosphoribosyl-transferase (HPRT: EC 2.4.2.8), which was identified in two brothers with hyperuricemia and nephrolithiasis. In previous studies, this mutant enzyme was characterized by an increased Km for both substrates, a normal Vmax, a decreased intracellular concentration of enzyme protein, a normal subunit molecular weight and an acidic isoelectric point under native isoelectric focusing conditions. We have cloned a full-length cDNA for HPRTAnn Arbor and determined its complete nucleotide sequence. A single nucleotide change (TG) at nucleotide position 396 has been identified. This transversion predicts an amino acid substitution from isoleucine (ATT) to methionine (ATG) in codon 132, which is located within the putative 5-phosphoribosyl-1-pyrophosphate (PRPP)-binding site of HPRT. 相似文献
4.
The AXB and BXA set of recombinant inbred mouse strains 总被引:1,自引:1,他引:0
Jan D. Marshall Jian-Long Mu Yin-Chai Cheah Muriel N. Nesbitt Wayne N. Frankel Beverly Paigen 《Mammalian genome》1992,3(12):669-680
The recombinant inbred (RI) set of strains, AXB and BXA, derived from C57BL/6J and A/J, originally constructed and maintained at the University of California/San Diego, have been imported into The Jackson Laboratory and are now in the 29th to 59th generation of brother-sister matings. Genetic quality control testing with 45 proviral and 11 biochemical markers previously typed in this RI set indicated that five strains had been genetically contaminated sometime in the past, so these strains have been discarded. The correct and complete strain distribution patterns for 56 genetic markers are reported for the remaining RI strain set, which consists of 31 living strains and 8 extinct strains for which DNA is available. Two additional strains, AXB 12 and BXA 17, are living and may be added to the set pending further tests of genetic purity. The progenitors of this RI set differ in susceptibility to 27 infectious diseases as well as atherosclerosis, obesity, diabetes, cancer, cleft palate, and hydrocephalus. Thus, the AXB and BXA set of RI strains will be useful in the genetic analysis of several complex diseases. 相似文献
5.
Effects of Systemically Administered Lithium on Phosphoinositide Metabolism in Rat Brain, Kidney, and Testis 总被引:15,自引:4,他引:11
William R. Sherman Ling Y. Munsell Beverly G. Gish Michael P. Honchar 《Journal of neurochemistry》1985,44(3):798-807
A single subcutaneous dose of 10 mEq/kg LiCl gives rise to an increase in the cerebral cortex level of myo-inositol-1-P (I1P) that closely follows cortical lithium levels and, at maximum, is 40-fold above the control value. Kidney and testis show smaller increases in I1P level following LiCl administration. The I1P level is still sixfold greater than that of untreated rat cortex 72 h later. In cortex, parallel increases also occur in myo-inositol-4-P (I4P) and myo-inositol 1,2-cyclic-P (cI1,2P), whereas myo-inositol-5-P (I5P) remains unchanged. The cortical increases in I1P and I4P levels are partially reversed by administering 150 mg/kg of atropine 22 h after the LiCl, treatment that does not affect cI1,2P. When doses of LiCl from 2 to 17 mEq/kg are given, the cerebral cortex levels of I1P and myo-inositol, measured 24 h later, are found to reach a plateau at about 9 mEq/kg of LiCl, whereas cortical lithium levels continued to increase with greater LiCl doses. Levels of all three of the brain phosphoinositides are unchanged by the 10 mEq/kg LiCl dose, as is the uptake of 32Pi into these lipids. Chronic dietary administration of LiCl for 22 days showed that the effects of lithium on I1P and myo-inositol levels persist for that period. Over the course of the chronic administration of the lithium, levels of I1P, myo-inositol, and of lithium in cortex remained significantly correlated. We believe that these increases in inositol phosphates result from endogenous phosphoinositide metabolism in cerebral cortex and that lithium is capable of modulating that metabolism by reducing cellular myo-inositol levels. The size of the effect is a function of both lithium dose and the degree of stimulation of receptor-linked phosphoinositide metabolism. This property of lithium may explain part of its ability to moderate the symptoms of mania. Our chronic study suggests that prolonged administration of LiCl does not result in compensatory changes in myo-inositol-1-P synthase or myo-inositol-1-phosphatase. 相似文献
6.
Spectrally pure reaction center preparations from Chloroflexus aurantiacus have been obtained in a stable form; however, the product contained several contaminating polypeptides. The reaction center pigment molecules (probably three bacteriochlorophyll a and three bacteriopheophytin a molecules) are associated with two polypeptides (Mr = 30000 and 28000) in a reaction center complex of Mr = 52000. No carotenoid is present in the complex. These data together with previous spectral data suggest that the Chloroflexus reaction center represents a more primitive evolutionary form of the purple bacterial reaction center, and that it has little if any relationship to the green bacterial component. A reaction center preparation from Rhodopseudomonas sphaeroides R26 was fully denatured at 50°C while the Chloroflexus reaction center required higher temperatures (70–75°C) for complete denaturation. Thus, an intrinsic membrane protein of a photosynthetic thermophile has been demonstrated to have greater thermal stability than the equivalent component of a mesophile. 相似文献
7.
Te-ning E. Liu Beverly Wolf John Geigert Saul L. Neidleman Janice D. Chin David S. Hirano 《Carbohydrate research》1983,113(1):151-157
The production of solid d-arabino-hexos-2-ulose (d-glucosone) from d-glucose by use of an enzyme, pyranose-2-oxidase (EC 1.1.3.10), is described. The enzyme is extracted from the mycelia of Polyporus obtusus, partially purified, and then immobilized on activated CH-Sepharose 4B. The enzymic conversion of d-glucose into d-glucosone is simple and convenient, and provides a product free from residual d-glucose. Lyophilization of the filtered reaction-solution yields the product, solid d-glucosone. Assay methods have been developed for monitoring the enzymic reaction and evaluating the purity of the final product. 相似文献
8.
Regulation of Tyrosyl-Transfer Ribonucleic Acid Synthetase in Bacillus subtilis 总被引:1,自引:1,他引:0 下载免费PDF全文
Derepression of tyrosyl-transfer ribonucleic acid synthetase in Bacillus subtilis was observed in strains grown with limiting tyrosine, but not in regulatory mutants derepressed in biosynthetic enzyme synthesis. 相似文献
9.
The activity of a new semisynthetic penicillin, α-carboxyl-3-thienylmethyl penicillin (BRL-2288) was determined against 535 clinical isolates of gram-negative bacilli, by using the tube dilution technique. Nearly 80% of isolates of Proteus spp. were inhibited by 3.12 μg or less of this antibiotic per ml. BRL-2288 was as active as ampicillin against Escherichia coli. It was slightly more active than carbenicillin or 6-(d-α-sulfoaminophenylacetamido)-penicillanic acid against Pseudomonas sp., with over half of the isolates being inhibited by 50 μg or less of BRL-2288 per ml. Isolates of Klebsiella sp. were routinely resistant to this antibiotic. The drug was bactericidal against most sensitive organisms. BRL-2288 was less active against large inocula. A strain of Pseudomonas sp. which developed resistance to carbenicillin also developed resistance to BRL-2288 simultaneously. 相似文献
10.
K Ogasawara W L Maloy B Beverly R H Schwartz 《Journal of immunology (Baltimore, Md. : 1950)》1989,142(5):1448-1456
A minor T cell determinant from pigeon cytochrome c, composed of residues 43 to 58 (p43-58), was synthesized along with a series of 48 analogs containing amino or carboxyl-terminal deletions or single amino acid substitutions. These peptides were analyzed functionally for their ability to elicit unique T cell populations on immunization of C57BL/10 mice and to stimulate a degenerate T cell clone capable of recognizing p43-58 in association with two different Ia molecules, A beta b:A alpha b and A beta d:A alpha d. These experiments allowed us to identify the residues in the determinant that are critical for T cell activation. Residues 50 and 52 had the dominant influence on T cell specificity, and residues 47, 48, 49, 51, and 53 had weak effects. Residues 46 and 54 were hardly recognized by the TCR at all, but appeared to influence the potency of the determinant by interacting with the Ia molecule. Finally, substitutions at positions 55 to 58 had no effect, but removal of these residues reduced the potency of the peptide, suggesting a contribution from the peptide backbone of this part of the molecule during T cell activation. An analysis of the spatial relationship of these dominant epitopic and agretopic residues suggests that this determinant does not assume a pure alpha-helical secondary structure when bound to the Ia molecule. 相似文献