PMID(sorted descending)
the mechanism of arsenate inhibition of the glucose active transport system in neurospora crassa. 2002123729
genetic alterations of ribonuclease-sensitive glycoprotein subunits of amino acid transport systems in neurospora crassa conidia. 2002123728
induction by rna of inositol independence in neurospora crassa.the effect of purified wild-type rna (allo-rna) on genetic reversion of inositol-requiring mutant 89601 of neurospora crassa is described. the mutant (inos minus) strain, on treatment with the wild-type rna preparation, was found to revert to wild type (inos+) in significant numbers. rna from the mutant (iso-rna) and allo-rna digested by rnase were ineffective in causing genetic reversion at the inositol locus. the allo-rna-induced revertants were stable and showed a mendelian transmission of th ...2002123644
genetic evidence on the organization and action of the qa-1 gene product: a protein regulating the induction of three enzymes in quinate catabolism in neurospora crassa.the first three reactions in the catabolism of qainic acid in neurospora crassa are under the genetic control of the qa gene cluster. this cluster consists of three structural genes encoding three inducible enzymes plus a regulatory gene (qa-1+) whose diffusible product apparently acts in a positive fashion to initiate coordinate synthesis of the three enzymes when an appropriate inducer is present. genetic and biochemical evidence for both complementing and temperature-sensitive qa-1 alleles in ...2002123642
ultraviolet-inactivation of conidia from heterokaryons of neurospora crassa containing uv-sensitive mutations.the effect of three uv-sensitive mutations of neurospora crassa, upr-i, uvs-4 and uvs-6, on the ultraviolet-inactivation of conidia from two-component heterokaryons was investigated. in two-component heterokaryons with wild-type sensitivity to radiation inactivation, all three conidial fractions exhibited similar ultraviolet-inactivation curves. each uv-sensitive mutation studied uniquely modified the ultraviolet-inactivation curves of conidia from two-component heterokaryons. in heterokaryons h ...2002123634
the subunit structure of tryptophan synthase from neurospora crassa.tryptophan synthase of neurospora crassa was purified to electrophoretic homogeneity from the wild type strain 74a which had been derepressed by the presence of 0.5 mm indoleacrylic acid in the growth medium. the isolated material migrated as a single symmetrical peak in the ultracentrifuge with a sedimentation constant of 6.0 s. gel filtration on sephadex g-200 and conventional sedimentation equilibirium yielded molecular weight estimates of 151,000 plus and minus 10,000 and 149,000 plus and mi ...1975123527
characterization of neurospora crassa mutants deficient in glucosephosphate isomerase.two independent mutants of neurospora crassa lacking glucosphosphate isomerase activity (gpi) were isolated. these mutants were obtained as double mutants containing the pp or t9 mutation in addition to the gpi mutation located on linkage group iv; the pp mutation caused the inability to form protoperithecium and the loss of ascospore germination, and the t9 mutation caused the alteration in glucoamylase and several growth characteristics. the gpi mutants did not grow on fructose but grew on glu ...1975123525
effects of ribonuclease a on amino acid transport in neurospora crassa.incubation of neurospora crassa conidia with ribonuclease (rnase) a reduces transport of l-phenylalanine by those cells. under similar conditions, oxidized rnase a, rnase t1, and rnase t2 do not have this effect. incubation of conidia with active rnase covalently attached to polyacrylamide beads reduces l-phenylalanine transport. this indicates that the site of enzymatic action is at the cell surface. at the lower concentration of enzyme used in this study, incubation with rnase a reduces transp ...1975123524
regulation of the purine catabolic enzymes in neurospora crassa. 1975123428
glucose transport-deficient mutant of neurospora crassa with an unusual rhythmic growth pattern.a new mutant of neurospora crassa has been isolated from the patch strain. the phenotype of the new mutant includes the periodic production of sparse and dense aerial hyphae and the inability to utilize carbohydrates. the biochemical lesion was identified as a deficiency in the low-affinity glucose transport system. the high-affinity transport system appeared normal. external conditions such as medium composition, temperature change, and light-dark cycles affected the rhythm of hyphal production ...1975123245
neurospora crassa temperature-sensitive mutant apparently defective in protein synthesis.a temperature-sensitive mutant of neurospora was isolated which appeared to be defective in the initiation of protein synthesis. the defect in mutant 34cts was apparently due to a single gene mutation, and was recessive in heterokaryons. conidial germination was normal and hyphal growth was nearly so in the mutant at 20 c, but both were greatly inhibited at 35 c. after 15 min at 35 c there was a reduced rate of protein synthesis, followed by decreases in ribonucleic acid and deoxyribonucleic aci ...2002123244
changes in the glutathione thiol-disulfide status of neurospora crassa conidia during germination and aging.improved methods were developed for the determination of reduced glutathione (gsh), glutathione disulfide (gssg), and protein-glutathione disulfide (pssg) and applied to determine the glutathione status at various stages of the asexual life cycle for the band strain of neurospora crassa. the gsh-gssg ratio in freshly harvested dry conidia was found to be about 150 but decreased to around 6 when dryconidia were aged (stored) for 10 days after harvest. when conidia were germinated, this ratio incr ...1975123243
regulation of 2-phosphoenolpyruvate carboxykinase and isocitrate lyase syntheses in neurospora crassa. 2002123004
isolation and characterization of neurospora crassa plasma membranes.the isolation and characterization of plasma membranes from a cell wall-less mutant of neurospora crassa are described. the plasma membranes are stabilized against fragmentation and vesiculation by treatment of intact cells with concanavalin a just prior to lysis. after lysis, the concanavalin a-stabilized plasma membrane ghosts are isolated by low speed centrifugation techniques and the purified ghosts subsequently converted to vesicles by removal of the bulk of the concanavalin a. the yield of ...1975122976
generation of adenosine triphosphate in cytochrome-deficient mutants of neurospora.the fungus neurospora crassa is known to possess a branched respiratory system consisting of the standard cytochrome chain and a cyanide-insensitive alternate oxidase. in the present experiments, the physiological function of the alternate oxidase has been analyzed by taking advantage of a number of cytochrome-deficient mutants, particularly poky f. respiration, cellular atp levels, and growth have been examined under the influence of three classes of inhibitors: inhibitors of the cytochrome cha ...1975122972
metabolism of pyrimidine deoxyribonucleosides in neurospora crassa.the experiments in this report involve the following series of reactions which were previously demonstrated with purified enzyme preparations from neurospora crassa: thymidine a yields thymine ribonucleoside b yields thymine c yields 5-hydroxymethyluracil d yields 5-formyluracil e yields uracil-5-carboxylic acid f yields uracil. the evidence for some of the reactions occurring in vivo has been incomplete and for others totally lacking. in this paper intact cells of neurospora are shown to be cap ...1975122971
genetic characterization of adenine-3 mutants induced by 4-nitroquinoline 1-oxide and 4-hydroxyaminoquinoline 1-oxide in neurospora crassa.specific locus mutations induced by the chemical carcinogens, 4-nitroquinoline 1-oxide (4nqo) and 4-hydroxyaminoquinoline 1-oxide (4haqo), have been characterized to obtain a presumptive identification of the genetic alterations at the molecular level. one hundred eighty-four 4nqo-induced and 219 4haqo-induced ad-3 mutants of neurospora crassa obtained in previous studies were studied with a series of genetic tests that permits determination of their genotype and the frequencies of point mutatio ...1975122814
an unstable allele of the am locus of neurospora crassa.the mutant strain am126 was isolated, using the direct selection procedure, after nitrous acid mutagenesis. it produced neither measurable nadp-dependent glutamate dehydrogenase (gdh) nor immunologically cross-reacting material. that the am126 strain produced some form of gdh product was shown by the fact that it complemented several other am mutant strains. the gdh formed by complementation between am126 and each of two other am mutants was relatively thermolabile, but could not be distinguishe ...200094569
electron microscopy of the rodlet layer of neurospora crassa conidia.neurospora crassa macroconidia possess a regularly arranged layer of small fibers (rodlets) near the spore surface. the structure and location of this layer were studied by making surface replicas, by negative staining, by freeze-fracturing and deep-etching, and by thin sectioning. when conidia were shaken vigorously in water, the layer fragmented and became separated from the surface in sheets. negative staining of such sheets showed that the individual rodlets have a hollow central core. when ...197993107
effect of n2 on the mutagenic and lethal activities of icr-170 in neurospora crassa.the nature of the n2 effect for icr-170, i.e., the greater mutagenic and lethal activities of this agent in the presence of n2 than o2, has been studied at the ad-3 region of neurospora crassa. the characteristics of the n2 effect for icr-170 were that (1) the n2 effect with icr-170 was displayed in conidia when n2 was administered during, but not before or after, icr-170 treatment, (2) the highly increased mutagenic and lethal activities of icr-170 in the presence of n2 were due to an anoxic co ...200190338
multiple intracellular peptidases in neurospora crassa.neurospora crassa possesses multiple intracellular peptidases which display overlapping substrate specificities. they were readily detected by an in situ staining procedure for peptidases separated in polyacrylamide gels, within which the auxilliary enzyme, l-amino acid oxidase, was immobilized. eleven different intracellular peptidases were identified by electrophoretic separation and verified by their individual patterns of substrate specificities. most peptide substrates tested were hydrolyze ...200086534
deficiency of subunit two of cytochrome oxidase in the mi-3 cytoplasmic mutant of neurospora crassa. 197772665
inhibition of germ tube formation in neurospora.phenethyl alcohol, m-cresol, and related compounds cause inhibition of germ tube formation in conidia of neurospora crassa. conidia continue to swell and form large spherical cells that are capable of multiple germ tube formation upon removal of inhibitor.197767112
mutagenicity of actinomycin d in neurospora crassa.actinomycin d is known to bind to native dna and is widely used as an antineoplastic agent and inhibitor of dna-dependent rna and protein synthesis. we report here the induction by actinomycin d of purple adenine-requiring mutants (ad-3) in wild-type neurospora crassa. a significant increase in the frequency of ad-3 mutants was evident when the organism was grown vegetatively in the presence of actinomycin d; the mutation frequency was at least 3.6 per 106 survivors. the actinomycin d-induced ad ...197555964
effects of antibiotics on the life cycle of neurospora crassa.some antibiotics and synthetic inhibitors affect, in several ways, the life cycle of neurospora crassa (germination of conidia leads to myceliar growth leads to formation of conidia). bikaverin, cyanein, scopathricin and phenethyl alcohol retard the germination of conidia, without inhibiting it completely. 5-fluorouracil, ramihyphin a and zygosporin a (cytochalasin d) do not inhibit the germination. bikaverin brings about a thickening of the hyphae of growing mycelium. ramihyphin a, cyanein, sco ...197551812
influence of n2 or o2 on two alkylating agents in neurospora crassa.previous studies have indicated that the alkylating agent, 2-methoxy-6-chloro-9-(3-[ethyl-2-chloroethyl]aminopropylamino)acridine dihydrochloride (icr-170), induces much more killing and mutation in conidia of neurospora crassa treated in an atmosphere of n2 than in an atmosphere of o2. it was desirable to determine if a similar effect--more killing and mutation in n2 than in o2--could be observed with two other known alkylating agents, beta-propiolactone (bpl) and ethyl methanesulfonate (ems), ...197549017
the genetic fine structure of the complex locus aro3 involved in early aromatic amino acid biosynthesis in schizosaccharomyces pombe.the complex locus aro3 of schizosaccharomyces pombe was subjected to genetical fine structure analysis. by comparing the complementation map and the meiotic recombination map, the aro3 locus could be subdivided into the five adjacent subregions a, b, c, d and e. out of 115 aro3 alleles, 26 nonsense alleles and 30 missense alleles could be identified by the criteria of nonsense suppressor sensitivity and leakiness, respectively. most alleles with a pleiotropic complementation pattern are of the n ...197945606
purification and some properties of uridine diphosphate n-acetylglucosamine pyrophosphorylase from neurospora crassa.uridine diphosphate n-acetylglucosamine pyrophosphorylase (ec. of neurospora crassa has been purified approximately 210-fold with dithiothreitol as the stabilizing agent by use of chromatographic techniques. the enzyme preparation appeared to be homogeneous when subjected to electrophoresis. the molecular weight was estimated as approximately 37 000 by gel filtration. the enzyme had an isoelectric point around ph 4.4. maximum activity of the enzyme was observed at ph 7.5. the enzyme re ...197943769
glutamine metabolism in nitrogen-starved conidia of neurospora crassa.during nitrogen deprivation, de novo synthesis of glutamine synthetase was induced in non-growing conidia of neurospora crassa. when ammonia or glutamine was added to conidia which had been deprived of nitrogen, glutamine and arginine accumulated at a higher rate than in condia not deprived of nitrogen. the degradation of exogenous glutamine to glutamate is apparently a necessary step in the accumulation of glutamine and arginine within the conidia. in non-growing conidia, a cycle probably opera ...197943352
regulation of glutamine synthetase messenger ribonucleic acid in connidia of neurospora crassa. 197943270
immunoelectrophoretic determination of nitrate reductase in neurospora crassa. 197940454
active transport of calcium in neurospora plasma membrane vesicles.functionally inverted plasma membrane vesicles isolated from the eukaryotic microorganism neurospora crassa catalyze mg2+/atp-dependent ca2+ uptake. inhibitors induced efflux studies and isotope-exchange experiments indicate that the ca2+ is accumulated inside the vesicles against a concentration gradient of about 40-fold, and that the majority of the transported ca2+ is present essentially in free solution. comparisons of mg2+/atp-driven 45ca2+ uptake and [14c]scn-uptake with respect to the mg2 ...197940223
the kinetics of a purified form of 3-deoxy-d-arabino heptulosonate-7-phosphate synthase (tryptophan) from neurospora crassa.1. a method is described for the purification of a form of 3-deoxy-d-arabinoheptulosonate-7-phosphate synthase (tryptophan) that probably differs from that of the native enzyme. 2. the kinetics of the reaction catalysed by 3-deoxy-d-arabinoheptulosonate-7-phosphate synthase (tryptophan) shows that the reaction proceeds via a ping-pong bi-bi mechanism, with activation by phosphoenolpyruvate (p-prv), the first substrate, and inhibition by erythrose 4-phosphate (ery-p) the second substrate. at low ...197939755
factors influencing the uptake of dna by neurospora crassa.under optimal conditions intact neurospora crassa cells incorporated nearly the same amount of 3h-labelled dna as that of the endogenous dna content of cells. after 18 h of incorporation more than 80 per cent of the radioactivity was retained in the cells. a maximum uptake of exogenous dna occurred at 28 degrees c, ph 6.35, in the presence of 100 mm calcium when the concentration of donor dna was 150 micrograms/ml. denatured dna was incorporated at a higher rate than native dna. the present find ...197839418
inhibition of the acid proteinase from neurospora crassa by diazoacetyl-dl-norleucine methyl ester, 1,2-epoxy-3-(4-nitrophenoxy)propane and pepstatin. 197938198
catalase of neurospora crassa. 1. induction, purification, and physical properties. 197937891
nitrogen metabolite repression of nitrate reductase in neurospora crassa: effect of the gln-1a locus.nicotinamide adenine dinucleotide phosphate (reduced form)-nitrate reductase was freed from ammonium repression in a neurospora crassa mutant having drastically lowered glutamine synthetase activity, gln-1a. the general phenomenon of nitrogen metabolite repression required glutamine or some aspect of glutamine metabolism.197937243
immunochemical characterization of glutamine synthetase from neurospora crassa glutamine auxotrophs.glutamine synthetase derived from two neurospora crassa glutamine auxotrophs was characterized. previous genetic studies indicated that the mutations responsible for the glutamine auxotrophy are allelic and map in chromosome v. when measured in crude extracts, both mutant strains had lower glutamine synthetase specific activity than that found in the wild-type strain. the enzyme from both auxotrophs and the wild-type strain was partially purified from cultures grown on glutamine as the sole nitr ...197937239
regulation of glutamate dehydrogenases in nit-2 and am mutants of neurospora crassa.the regulation of the glutamate dehydrogenases was investigated in wild-type neurospora crassa and two classes of mutants altered in the assimilation of inorganic nitrogen, as either nitrate or ammonium. in the wild-type strain, a high nutrient carbon concentration increased the activity of reduced nicotinamide adenine dinucleotide phosphate (nadph)-glutamate dehydrogenase and decreased the activity of reduced nicotinamide adenine dinucleotide (nadh)-glutamate dehydrogenase. a high nutrient nitr ...197935517
nitrogen-metabolizing enzymes of diplodia maydis, a zea mays l. stalk rot causing fungus.the nitrogen source available to diplodia maydis in vivo is reported to affect the severity of stalk rot in maize. nitrate and (or) ammonium salts were tested for their effect on the type of nitrogen metabolism found in diplodia maydis in vitro. the level of glutamate dehydrogenase remained essentially constant on either nitrogen salt but nitrate reductase was induced by growth on nitrate salts and was not extractable on ammonium salts. properties of nitrate reductase reported here are similar t ...197935273
subunit ratios of separated hybrid hexamers of neurospora nadp-specific glutamate dehydrogenase containing complementing mutationally modified monomers.the am1 and am3 mutational variants of the neurospora crassa nadp-specific glutamate dehydrogenase show complementation activity in hybrid hexamers. a freeze-thaw hybridization method was used to construct hybrids from purified enzymes and the products were separated into species of different monomer ratio by affinity chromatography. hexamers with am1:am3 ratios of 1:5, 2:4, 3:3, 4:2 and 5:1 were all recovered as resolved or partially resolved peaks in quantities approximating to a binomial dist ...197833665
purification and studies of some physicochemical properties of glutamine synthetase of neurospora crassa.glutamine synthetase (ec of neurospora crassa was purified to near homogeneity by chromatography on a glutamate-sepharose affinity column. its properties, including molecular weight, subunit structure, amino acid composition, and approximate alpha-helix content, have been examined. in the native state, this enzyme has been demonstrated by gel filtration to be an octamer of molecular weight 360,000 and as having a sedimetation coefficient of 13.2 s by sedimentation velocity measurements. ...197831969
nitrogen source regulates glutamine synthetase mrna levels in neurospora crassa.neurospora crassa glutamine synthetase mrna was measured by its capacity to direct the synthesis of the specific protein in a cell-free system derived from rabbit reticulocytes. n. crassa cultures grown on glutamate as the sole nitrogen source had higher mrna activities than did those grown on glutamine. the differences were about 10-fold when polysomal rna was used for translation and about 5-fold when either total cellular rna or polyadenylic acid-enriched cellular rna was used. these data ind ...197831352
purification and properties of dna-dependent dna-polymerases from neurospora crassa.two dna-dependent dna-polymerases (e.c. are partially purified from the high speed supernatant of mechanically disrupted hyphae of neurospora crassa wt 74a. some properties such as temperature and ph optimum and theoptimal concentrations for mg2+, zn2+, nh4+ and na+ are very similar. on the other hand these enzymes show different properties on ion-exchange columns, are well distinguished by molecular weight (147 000 d and 110 000 d for a and b resp.) and the stimulation by k+ differs (k ...197829281
kinetic properties of pyruvate kinase of neurospora crassa at physiological ph.the kinetic properties of pyruvate kinase (ec extracted from the mycelia of neurospora crassa were examined at physiological ph to determine the role of the enzyme in the regulation of glycolysis. the velocity curve with the substrates, phosphoenolpyruvate and adenosine diphosphate, are hyperbolic. the effect of magnesium, potassium, or calcium on the enzyme is influenced by the ph but not to the extent that would change their role as cofactor or inhibitor. adenosine triphosphate and c ...197827701
nitrogen regulation of glutamine synthetase in neurospora crassa.a higher activity of glutamine synthetase (ec was found in neurospora crassa when nh4+ was limiting as nitrogen source than when glutamate was limiting. when glutamate, glutamine or nh4+ were in excess, a lower activity was found. immunological titration and sucrose gradient sedimentation of the enzyme established that under all these conditions enzyme activity corresponded to enzyme concentration and that the octamer was the predominant oligomeric form. when n. crassa was shifted from ...199827575
isolation of a multiprotein complex containing cytochrome b and c1 from neurospora crassa mitochondria by affinity chromatography on immobilized cytochrome c. difference in the binding between ferricytochrome c and ferrocytochrome c to the multiprotein complex.a multiprotein complex which contains in equimolar amounts two cytochromes b (mr each about 27,000), one cytochrome c1 (mr 31,000) and six subunits without known prosthetic groups (mr 8000, 12,000, 14,000, 45,000, 45,000, and 50,000) has been isolated from the mitochondrial membranes of neurospora crassa by affinity chromatography on immobilized cytochrome c. the chromatographic separation was based upon the specific binding of the complex to ferricytochrome c coupled to sepharose and its specif ...197827360
genetics and physiology of neurospora crassa glutamine auxotrophs.this work reports on the isolation and characterization of two glutamine auxotrophs in neurospora crassa. the mutations responsible for the glutamine-requiring phenotype were very closely linked, and one of them proved to be recessive to wild type. the mutations impaired the conversion of glutamic acid to glutamine and resulted in changes of both the activity and oligomeric structure of the enzyme glutamine synthetase.197826664
purification and characterization of homogeneous assimilatory reduced nicotinamide adenine dinucleotide phosphate-nitrate reductase from neurospora crassa.neurospora crassa wild type sta4 nadph-nitrate reductase (nadph : nitrate oxidoreductase, ec has been purified 5000-fold with an overall yield of 25--50%. the final purified enzyme contained 4 associated enzymatic activities: nadph-nitrate reductase, fadh2-nitrate reductase, reduced methyl viologen-nitrate reductase and nadph-cytochrome c reductase. polyacrylamide gel electrophoresis yielded 1 major and 1 minor protein band and both bands exhibited nadph-nitrate and reduced methyl violo ...197826408
role of metal cofactors in enzyme regulation. differences in the regulatory properties of the neurospora crassa nicotinamide adenine dinucleotide specific isocitrate dehydrogenase depending on whether mg2+ or mn2+ serves as divalent cation. 197825669
current-voltage relationships for the plasma membrane and its principal electrogenic pump in neurospora crassa: i. steady-state conditions.the nonlinear membrane current-voltage relationship (i-v curve) for intact hyphae of neurospora crassa has been determined by means of a 3-electrode voltage-clamp technique, plus "quasi-linear" cable theory. under normal conditions of growth and respiration, the membrane i-v curve is best described as a parabolic segment convex in the direction of depolarizing current. at the average resting potential of - 174 mv, the membrane conductance is approximately 190 micronhos/cm2; conductance increase ...199825343
mitochondrial adenosine triphosphatase of wild-type and poky neurospora crassa.we have compared the adenosine triphosphatase (atpase) activity of mitochondria prepared from wild-type neurospora crassa and from poky, a maternally inherited mutant known to possess defective mitochondrial ribosomes and reduced amounts of cytochromes aa3 and b. poky contains two distinct forms of mitochondrial atpase. the first is normal in its km for atp, specificity for nucleotides and divalent cations, ph optimum, cold stability, and sensitivity to inhibitors (oligomycin, n,n-dicyclohexyl c ...197824038
biosynthesis of glycogen in neurospora crassa. purification and properties of the udpglucose:glycogen 4-alpha-glucosyltransferase.the neurospora crassa glycogen synthase (udpglucose:glycogen 4-alpha-glucosyltransferase, ec was purified to electrophoretic homogeneity by a procedure involving ultracentrifugation, deae-cellulose column chromatography, (nh4)2so4 fractionation and 3-aminopropyl-sepharose column chromatography. the final purified enzyme preparation was almost entirely dependent on glucose-6-p and had a specific activity of 6.9 units per mg of protein. the subunit molecular weight of the glycogen syntha ...197823841
[nicotinamide coenzymes at the early stages of light induction of carotenogenesis in the neurospora crassa mycelium].changes in the concentration of nad+, nadh, nadp+ and nadph in the mycelium of the nadase free mutant of neurospora crassa were studied during the latent stage of light induction of carotenogenesis. a 30 minute illumination by visible light brought about a stable decrease in the nadh/nad+nadh ratio, exerting no effect on the nadph/nadp+nadph ratio. at the same time the nadp+/nad+ ratio increased. these changes occurred only when illumination induced carotenoid accumulation in the n. crassa mycel ...201323524
affinity chromatography of the neurospora nadp-specific glutamate dehydrogenase, its mutational variants and hybrid hexamers.the synthesis of an affinity adsorbent, 8-(6-aminohexyl)aminoadenosine 2'-phosphate-sepharose 4b, is described. the assembly of the 2'-amp ligand and the hexanediamide spacer arm was synthesized in free solution before its attachment to the sepharose matrix. this adsorbent retarded the hexameric nadp-specific glutamate dehydrogenase of neurospora crassa, showing a capacity for this enzyme similar to that of comparable coenzyme-analogue adsorbents for other dehydrogenases. the enzyme was eluted e ...199922328
neurospora crassa glutamine synthetase. role of enzyme synthesis and degradation on the regulation of enzyme concentration during exponential growth.the specific activity of neurospora crassa glutamine synthetase varies according to the nitrogen source in which the organism is grown. in a poor nitrogen source such as glutamate, the specific activity of the enzyme is higher than that found in good nitrogen sources such as ammonium or glutamine. these differences in specific enzyme activity correspond to differences in enzyme concentration. the relative rates of glutamine synthetase synthesis and degradation were measured in exponential cultur ...199921883
metabolism of mandelic acid by neurospora crassa.preliminary studies on the metabolism of manelic acid by neurospora crassa reveal the operation of a pathway for its degradation which involves benzoyl formic acid, benzaldehyde, benzoic acid, 4-hydroxybenzoic acid, and protocatechuic acid as the intermediates. this pathway is different from the followed by bacterial systems and is the same as that observed in aspergillus niger.197721739
characterization of the aspartate carbamoyltransferase fragment generated by protease action on the pyrimidine-3 gene product of neurospora crassa.the molecular weight of the fragment of aspartate carbamoyltransferase (carbamoylphosphate: l-aspartate carbamoyltransferase, ec of neurospora crassa following proteolysis was found to be 1.0-10(5) (aspartate carbamoyltransferase-l). it differs from the native form of the enzyme (aspartate carbamoyltransferase-n, 6.5-10(5)) in several respects. it has a lower v, has a much greater affinity (approx. 3-fold) for l-aspartate, and is strongly activated by glycine. both forms of aspartate ca ...199821697
regulation of glutamine synthetase in fed-batch cultures of neurospora crassa. 197721661
nicotinamide adenine dinucleotide-specific glutamate dehydrogenase of neurospora. iv. the cooh-terminal 669 residues of the peptide chain; comparison with other glutamate dehydrogenases.a sequence is presented for the cooh-terminal 669 residues of the nad-specific glutamate dehydrogenase of neurospora crassa. comparison of this sequence with those of the vertebrate glutamate dehydrogenases of chicken and bovine liver and with the nadp-specific enzyme of neurospora shows some similarities in sequences around residues previously identified as important for the function of these enzymes. these are: (a) the reactive lysine residue of low pk in the nadp and the vertebrate enzymes; ( ...197721191
biosynthesis of glycogen in neurospora crassa. existence of a glucoproteic intermediate in the initiation process.a soluble enzyme preparation (20,000 x g supernatant fraction), prepared from the mycelia of wild-type neurospora crassa, was capable of transferring [14c]glucose from udp-[14c]glucose into both trichloroacetic acid (tca)-soluble and tca-insoluble macromolecule products in the absence of added primer. these reactions did not require either high concentrations of salts or any other chemical reagents. two labeled products were formed; one was a glycogen-like polysaccharide and the other was a glyc ...197719440
regulation of the neurospora crassa assimilatory nitrate reductase.reduced nicotinamide adenine dinucleotide phosphate (nadph)-nitrate reductase from neurospora crassa was purified and found to be stimulated by certain amino acids, citrate, and ethylenediaminetetraacetic acid (edta). stimulation by citrate and the amino acids was dependent upon the prior removal of edta from the enzyme preparations, since low quantities of edta resulted in maximal stimulation. removal of edta from enzyme preparations by dialysis against chelex-containing buffer resulted in a lo ...199819423
amino acid replacements resulting from suppression and missense reversion of a chain-terminator mutation in neurospora.the neurospora crassa super-suppressor mutation, ssu-1, suppresses the auxotrophic phenotype of the mutant am(17) by inserting tyrosine at residue 313 of nadp-specific glutamate dehydrogenase, a position occupied in the wild type by glutamate. two classes of am(17) revertants due to further mutation within the am gene have, respectively, tyrosine and leucine at residue 313. these replacements are consistent with a chain-terminating codon in am(17) of either the amber (uag) or the ochre type (uaa ...197718380
properties of neurospora crassa plasma membrane atpase. 197718094
isocitrate lyase from neurospora crassa: ph dependence of catalysis and interaction with substrates and inhibitors. 197718092
characterization of plasma membrane adenosine triphosphatase of neurospora has been proposed (slayman, c.l., long w.s., and lu, c.y.-h. (1973) j. membr. biol. 14, 305--338) that in neurospora crassa, a plasma membrane atpase functions to pump h+ ions out of the cell, thereby generating an electrochemical gradient that can drive transport processes. using the concanavalin a method of scarborough (scarborough g.a. (1975)j. biol. chem. 250, 1106--1111), we have prepared plasma membranes of neurospora and have deomonstrated that they do contain a distinct atpase activit ...197716897
the stereospecificity of nitrate reductase for hydrogen removal from reduced pyridine nucleotides.the stereospecificity of the hydrogen removal from reduced pyridine nucleotides catalyzed by nitrate reductase (nadh : nitrate oxidoreductase, ec, and nad(p)h : nitrate oxidoreductase, ec was investigated. a high degree of enzyme purification was required to obtain conclusive results. improvements are described for the purification of nitrate reductase from chlorella fusca and from spinach (spinacea oleracea, l.) leaves. the latter enzyme is shown to contain a cytochrome. with h ...197716653
neurospora crassa glutamine synthetase. translation of specific messenger ribonucleic acid in a cell-free system derived from rabbit reticulocytes.the total reticulocyte lysate cell-free protein-synthesizing system was incubated in the presence of neurospora crassa rna. with the aid of an antibody directed against purified n. crassa glutamine synthetase, the synthesis of a specific protein was detected. this protein precipitates with antiglutamine synthetase using both direct and indirect procedures, migrates with the same molecular weight as the monomer of n. crassa glutamine synthetase when subjected to acrylamide gel electrophoresis in ...197716013
cellulase of neurospora crassa.mycelia and ungerminated conidia of neurospora crassa were found to secrete extracellular endocellulase (ec a simple induction system of potassium phosphate buffer (ph 6.0) plus inducer relied on the internal metabolic reserves of conicia or mycelia to provide energy and substrates for protein synthesis. buffer concentration for optimum enzyme production was 100 mm, but at higher buffer concentrations enzyme production was inhibited. cellobiose was clearly the best inducer, with an opt ...200015975
[adenine uptake in neurospora crassa mycelium].the uptake of 8-c14-adenine in n. crassa strain lindegren (+) was studied. the ability of n. crassa cells to uptake adenine from the medium reaches maximum at the very beginning of the logarithmic stage of growth. adenine enters the mycelium against the concentration gradient. the uptake of adenine is maximal at 25-30 degrees c, ph 4,6-4,8, and adenine concentration in the medium about 2-15x10(-6) m. the entry of adenine into the cells follows normal michaelis-menten kinetics, the apparent km=0. ...197715650
[isolation and properties of tripolyphosphatase from neurospora crassa].homogenous preparation of tripolyphosphatase from neurospora crassa is obtained. the enzyme is found to consist of two equal subunits with molecular weight of 40 000 and to have ph optimum 7.0 and temperature optimum 50 degrees c. bivalent metal ions are required for its catalytical activity, the hest activators being co2+, mg2+ and mn2+. strict specificity of the enzyme to tripolyphosphate is demonstrated, km being 5.9-10(-4) m. the enzyme hydrolyses tripolyphosphate to equimolar mixture of ort ...200114720
isolation and characterization of a mitochondrial d-amino acid oxidase from neurospora crassa.d-amino acid oxidase (ec activity in homogenates of neurospora crassa strain sy7a was found to sediment with the mitochondrial fraction. digitonin fractionation studies on purified mitochondria have indicated a matrix localization of the enzyme. additionally, a peroxidase (ec activity, which may remove hydrogen peroxide formed as a product of d-amino acid oxidation, was also found in the mitochondrial matrix. partial purification (20- to 30-fold) of the mitochondrial d-amino a ...200013919
lytic enzymes in the autolysis of filamentous fungi.the degrees of autolysis attained by five different genera of filamentous fungi during an incubation period of 60 days, under the same culture conditions were: 87.3% for penicillium oxalicum; 65.9% for neurospora crassa; 62.7% for polystictus versicolor; 51.7% for aspergillus niger and 23.5% for nectria galligena. n. crassa, a. niger and p. versicolor reached the end of the autolysis during this incubation period (60 days), whereas p. oxalicum and n. galligena did not. the excretion of the lytic ...197613304
electron spin resonance investigations of mitochondrial electron transport in neurospora crassa. characterization of paramagnetic intermediates in a standard strain.1. submitochondrial particles from neurospora strain inl-89601 have been analyzed by electron spin resonance spectroscopy (esr). numerous signals due to iron-sulfur proteins are observed at low temperatures. analysis of these esr signals at various temperatures allows the assignment of resonances to iron-sulfur centers 1-5 that have been described in other organisms. there are no discrepancies between the signals seen in neurospora and those described in other organisms and it is likely that neu ...197612965
reactions of the neurospora crassa nitrate reductase with nad(p) analogs.the assimilatory nadph-nitrate reductase (nadph:nitrate oxidoreductase, ec from neurospora crassa is competitively inhibited by 3-aminopyridine adenine dinucleotide (aad) and 3-aminopyridine adenine dinucleotide phosphate (aadp) which are structural analogs of nad and nadp, respectively. the amino group of the pyridine ring of aad(p) can react with nitrous acid to yield the diazonium derivative which may covalently bind at the nad(p) site. as a result of covalent attachment, diazotized ...197712830
biphasic interactions between a neurospora crassa glutamate dehydrogenase and reduced nicotinamide-adenine dinucleotide phosphate. 197612047
mutational amino acid replacements in neurospora crassa nadp-specific glutamate dehydrogenase. 19769517
identification of a functional arginine residue involved in coenzyme binding by the nadp-specific glutamate dehydrogenase of neurospora.the nadp-specific glutamate dehydrogenase (ec of neurospora crassa is inhibited by reaction with 1,2-cyclohexanedione which binds to arginine residues. with the 14c-labeled reagent, a peptide was isolated with the sequence: gly-gly-leu-arg-leu-his-pro-ser-val-asn-leu, corresponding to residues 78 through 88 in the protein. the arginine, residue 81, was present as n7,n8-(1,2-dihydroxycyclohex-1,2-ylene)-arginyl (or dhch-arginine). present evidence indicates that this arginine residue res ...19769404
ageing of neurospora crassa. iv. induction of senescence in wild type by dietary amino acid analogs and reversal by antioxidants and membrane stabilizers.the extensional growth rate of wild-type 74a8 n. crassa in the presence of various concentrations of 19 amino acid analogs was measured. seven analogs were not inhibitory at concentrations in the range of one to 10mm. of the remaining 12 analogs, nine inhibited growth in a novel way. the kinetics of growth in the presence of these analogs at 30 degrees were characterized by seven sequential phases: (1)lag; (2) acceleration of growth rate; (3) steady-state growth rate; (4) exponential rate of dec ...20157715
neurospora crassa glutamine synthetase. purification by affinity chromatography and characterization of subunit structure.neurospora crassa glutamine synthetase was purified to homogeneity by a procedure based on affinity chromatography. the enzyme is adsorbed to a matrix of anthranilic acid bound to sepharose and eluted with amp. different experimental approaches indicate that the enzyme has an octameric structure formed by subunits of identical molecular weight.19767567
modification of the regulatory properties of pyruvate kinase of neurospora by growth at elevated temperatures.pyruvate kinase (ec was isolated from neurospora crassa mycelium grown at 28 degrees c (pk-28) and at 42 degrees c (pk-42). the regulatory properties, particularly the response towards the allosteric effector fructose 1,6-diphosphate (fdp), was different in the two enzymes. pk-28 showed an activation by fdp but pk-42, under comparable conditions, appeared to be activated by low concentrations of fdp and inhibited by higher ones. for pk-28, complex formation with fdp results in a loweri ...19766132
control of the formation of extracellular ribonuclease in neurospora crassa.a finding was made that a species of ribonuclease is released into mycelial culture media when a wild-type strain of neurospora crassa was grown on limiting amounts of phosphate. the ribonuclease activity in the fully derepressed state extends to about 60 to 100 fold of that in the repressed state. the synthesis of the ribonuclease was inhibited by the addition of rifampicin, cycloheximide or orthophosphate. three molecular species of the ribonuclease were found. two enzyme fractions showing lar ...19765154
role of mannosyl lipid intermediate in the synthesis of neurospora crassa glycoproteins.particulate membrane preparations from neurospora crassa incorporated mannose from gdp-[14c] mannose into endogenous lipid and particulate protein acceptors. synthesis of the mannosyl lipid is reversible in the presence of gdp. chemical and chromatographic characterization of the mannosyl lipid suggest that it is a mannosylphosphorylpolyisoprenol. the other endogenous acceptor was precipitated by trichloracetic acid. gel filtration and electrophoresis studies before and after treatment with prot ...19765115
biochemical genetics of neurospora crassa conidial germination. 19765072
lysophospholipase activity in cell-wall fragments contaminating mitochondrial fractions of neurospora crassa.crude mitochondrial preparations from neurospora crassa contain high levels of lysophospholipase (ec activity when assayed with lysophosphatidylcholine as a substrate. in mitochondria purified by centrifugation on a sucrose-density gradient this activity is virtually absent. the enzyme was shown to be linked to a contaminating cell fraction which mainly consists of cell-wall material as was demonstrated by electron microscopy and chemical analysis. the enzyme has no absolute ca2+ requir ...19763219
[isolation and properties of polyphosphatase of neurospora crassa].polyphosphatase (polyphosphate-phosphohydrolase) has been isolated from mycelium of neurospora crassa and purified to homogenous state. the enzyme is shown to be strictly specific to high molecular weight inorganic polyphosphates. km for phosphate in polymeric form is 6.8-10(-4) m. the molecular weight of this enzyme is 50 000 +/- 3000. to display its activity polyphosphatase requires the presence of bivalent cations of some metals, mg2+ ions being the best activator with co2+, mn2+ and fe2+ ion ...20162861
the amino acid sequence of neurospora nadp-specific glutamate dehydrogenase. peptic and chymotryptic peptides and the complete sequence.peptic and chymotryptic peptides were isolated form the nadp-specific glutamate dehydrogenase of neurospora crassa and substantially sequenced. out of 452 residues in the polypeptide chain, 265 were recovered in the peptic and 427 in the chymotryptic peptides. together with the tryptic peptides [wootton, j. c., taylor, j. g., jackson, a. a., chambers, g. k. & fincham, j. r. s. (1975) biochem. j. 149, 749-755], these establish the complete sequence of the chain, including the acid and amide assig ...19751002
the amino acid sequence of neurospora nadp-specific glutamate dehydrogenase. peptides from digestion with a staphylococcal proteinase.the extracellular proteinase of staphylococcus aureus strain v8 was used to digest the nadp-specific glutamate dehydrogenase of neurospora crassa. of 35 non-overlapping peptides expected from the glutamate content of the polypeptide chain, 29 were isolated and substantially sequenced. the sequences obtained were valuable in providing overlaps for the alignment of about two-thirds of the sequences found in tryptic peptides wootton, j. c., taylor, j, g., jackson, a. a., chambers, g. k. & fincham, ...19751001
the amino acid sequence of neurospora nadp-specific glutamate dehydrogenase. the tryptic peptides.the nadp-specific glutamate dehydrogenase of neurospora crassa was digested with trypsin, and peptides accounting for 441 out of the 452 residues of the polypeptide chain were isolated and substantially sequenced. additional experimental detail has been deposited as supplementary publication sup 50052 (11 pages) with the british library (lending division), boston spa, wetherby, w. yorkshire ls23 7bq, u.k., from whom copies may be obtained under the terms given in biochem j. (1975) 145, 5.19751000
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