Isolation and Characterization of Glycerol-3-Phosphate Dehydrogenase-Defective Mutants of Neurospora crassa

Three glycerol-nonutilizing mutants deficient in the mitochondrial glycerol-3-phosphate (G3P) dehydrogenase (EC 1.1.99.5) were isolated from inl(ts) derivatives of Neurospora crassa following inositolless death at elevated temperatures on minimal glycerol medium. These mutants failed to grow on glycerol as a sole carbon source, but could grow on acetate, glucose, or mannitol media and were female fertile in genetic crosses, thereby distinguishing them from the previously reported polyol-protoperithecial defective Neurospora mutants. In addition, these glp mutants exhibited a distinct morphological alteration during vegetative growth on sucrose slants and colonial growth on sorbose-containing semicomplete medium. The glp-2 locus was assigned a location between arg-5 and nuc-2 on chromosome IIR on the basis of two-factor crosses and by duplication coverage by insertional translocation ALS176, but not NM177. All mutations were allelic as judged from the absence of both complementation in forced heterokaryons and genetic recombination among glp-2 mutations. The reversion frequency of all three mutations was less than 10(10), indicating probable deletions in these strains. No G3P dehydrogenase activity could be detected in either cytosolic or mitochondrial extracts from mutant strains grown on glycerol, glucose, or galactose media. These results suggest that the glp-2 locus may be the structural gene for both the cytosolic and mitochondrial forms of G3P dehydrogenase or for a cytosolic precursor of the mitochondrial G3P dehydrogenase. The defect is specific for the G3P dehydrogenase since normal activities of the mitochondrial cytochrome oxidase and succinate dehydrogenase and the cytosolic glycerol dehydrogenase and dihydroxyacetone phosphate reductase are detected in mutant extracts. During attempted growth of glp-2 mutants on glycerol media, there was an accumulation of G3P in culture filtrates, a reduction in the mycelial growth rate, and a decreased level of glycerokinase induction.     

Two homologous regulatory genes, lin-12 and glp-1, have overlapping functions.

Two homologous genes, lin-12 and glp-1, encode transmembrane proteins required for regulatory cell interactions during C. elegans development. Based on their single mutant phenotypes, each gene has been thought to govern a distinct set of cell fates. We show here that lin-12 and glp-1 are functionally redundant during embryogenesis: Unlike either single mutant, the lin-12 glp-1 double mutant dies soon after hatching. Numerous cellular defects can be observed in these Lag (for lin-12 and glp-1) double mutants. Furthermore, we have identified two genes, lag-1 and lag-2, that appear to be required for both lin-12 and glp-1-mediated cell interactions. Strong loss-of-function lag mutants are phenotypically indistinguishable from the lin-12 glp-1 double; weak lag mutants have phenotypes typical of lin-12 and glp-1 single mutants. We speculate that the lin-12 and glp-1 proteins are biochemically interchangeable and that their divergent roles in development may rely largely on differences in gene expression.     

Characterization of glycerol nonutilizing and protoperithecial mutants ofNeurospora

Summary Mutants defective in polyol metabolism and/or in protoperithecial development were selected inNeurospora tetrasperma, a species in which protoperithecial development occurs at nonpermissively high temperature if certain polyols are used in lieu of sucrose as carbon source. Mutants selected for nonutilization of one of the four polyols tested, glycerol, mannitol, sorbitol, or xylitol, were usually found to be nonutilizers of the other three polyols as well. Mutants blocked at various stages of protoperithecial development complemented pairwise to produce more advanced developmental stages, usually mature protoperithecia and, when of opposite mating type, mature perithecia. About one-third of the mutants manifested both polyol auxotrophy and defective protoperithecial development upon initial isolation, but protoperithecial defectiveness in such mutants usually showed erratic segregation in crosses and/or instability to repeated vegetative transfer, whereas polyol auxotrophy usually did not and was, therefore, studied further. Two glycerol nonutilizing strains were introgressed intoN. crassa to facilitate genetic analysis. One,glp-4, lacked both inducible and constitutive glycerol kinase and mapped to linkage group VI, betweenad-1 andrib-1; the other,glp-5, lacked glyceraldehyde kinase and mapped to linkage group I, proximal toad-9. Another mutant,gly-u(234), has been reported by other investigators to lack inducible glycerol kinase but to map to linkage group I, distal toad-9.     

Fluorometric procedures for measuring triglyceride concentrations in small amounts of tissue and plasma

It has been previously shown that triglycerides can be specifically hydrolyzed by lipase from Rhizopus arrhizus in the presence of hog liver esterase and sodium dodecyl sulfate. The glycerol produced can then be measured by sequential reactions with glycerokinase, pyruvate kinase, and lactate dehydrogenase: glycerol and ATP are converted to glycerol-3-phosphate and ADP by glycerokinase; the ADP reacts with phosphoenolpyruvate and pyruvate kinase to yield pyruvate; the pyruvate is converted to lactate with lactate dehydrogenase, and the cofactor NAD+ is simultaneously reduced to NADH. This report describes procedures by which either the disappearance of NADH or the appearance of NAD+ was determined fluorometrically, with 10- to 100-fold greater sensitivity than by spectrophotometry. In addition, enzymatic cycling of NAD+ was used to increase the sensitivity of the assay over 1000-fold, and thereby provided accurate measurement of less than 1 ng of triglyceride. Results obtained from the three fluorometric methods were highly correlated with an automated periodate oxidation method using serum samples and lipid extracts of muscle tissue.     

Genetic analysis of Caenorhabditis elegans glp-1 mutants suggests receptor interaction or competition

glp-1 encodes a member of the highly conserved LIN-12/Notch family of receptors that mediates the mitosis/meiosis decision in the C. elegans germline. We have characterized three mutations that represent a new genetic and phenotypic class of glp-1 mutants, glp-1(Pro). The glp-1(Pro) mutants display gain-of-function germline pattern defects, most notably a proximal proliferation (Pro) phenotype. Each of three glp-1(Pro) alleles encodes a single amino acid change in the extracellular part of the receptor: two in the LIN-12/Notch repeats (LNRs) and one between the LNRs and the transmembrane domain. Unlike other previously described gain-of-function mutations that affect this region of LIN-12/Notch family receptors, the genetic behavior of glp-1(Pro) alleles is not consistent with simple hypermorphic activity. Instead, the mutant phenotype is suppressed by wild-type doses of glp-1. Moreover, a trans-heterozygous combination of two highly penetrant glp-1(Pro) mutations is mutually suppressing. These results lend support to a model for a higher-order receptor complex and/or competition among receptor proteins for limiting factors that are required for proper regulation of receptor activity. Double-mutant analysis with suppressors and enhancers of lin-12 and glp-1 further suggests that the functional defect in glp-1(Pro) mutants occurs prior to or at the level of ligand interaction.     

Identification of genes that interact with glp-1, a gene required for inductive cell interactions in Caenorhabditis elegans

The glp-1 gene functions in two inductive cellular interactions and in development of the embryonic hypodermis of C. elegans. We have isolated six mutations as recessive suppressors of temperature-sensitive (ts) mutations of glp-1. By mapping and complementation tests, we found that these suppressors are mutations of known dumpy (dpy) genes; dpy genes are required for development of normal body shape. Based on this result, we asked whether mutations previously isolated in screens for mutants defective in body shape could also suppress glp-1(ts). From these tests, we learned that unselected mutations of eight genes required for normal C. elegans morphogenesis, including the four already identified, suppress glp-1(ts). All of these suppressors rescue all three mutant phenotypes of glp-1(ts) (defects in embryonic induction of pharyngeal tissue, in embryonic hypodermis development, and in induction of germline proliferation). However, they do not rescue putative glp-1 null mutants and therefore do not bypass the requirement for glp-1 in development. In the light of current ideas about the molecular nature of the glp-1 and suppressor gene products, we propose an interaction between the glp-1 protein and components of the extracellular matrix and speculate that this interaction may impose spatial constraints on the decision between mitosis and meiosis in the germline.     

Characterization of a germ-line proliferation mutation in C. elegans.

The C. elegans germ line is generated by extensive proliferation of the two germ-line progenitor cells present in newly hatched larvae. We describe genetic and phenotypic characterization of glp-4, a locus whose product is required for normal proliferation of the germ line. glp-4(bn2ts) mutant worms raised at the restrictive temperature contain approximately 12 germ nuclei, in contrast to the 700-1000 present in wild-type adults. The few germ cells present in sterile glp-4 adults appear to be arrested at prophase of the mitotic cell cycle. This cell-cycle disruption prevents the germ cells from entering meiosis and differentiating into gametes. Shifting sterile glp-4 worms to the permissive temperature enables their germ cells to undergo extensive proliferation and form gametes, demonstrating that the bn2-induced cell-cycle arrest is reversible and that proliferation and differentiation of germ cells can be uncoupled from development of the somatic gonad. The glp-4(bn2ts) mutation can be used to generate large populations of worms that are severely depleted in germ cells, facilitating determination of whether any gene of interest is expressed in the germ line or soma or both.     

Characteristics of a glycerol utilization mutant of Neurospora crassa.

A mutant of Neurospora crassa able to grow on liquid minimal glycerol medium without evidence of conidiation and with high cell yields has been isolated and shown to be allelic to ff-1. The glycerol-specific induction of glycerokinase and glycerol-3-phosphate dehydrogenase was similar in both wild-type and mutant cells, although higher specific activities as well as higher glycerokinase cross-reacting material levels were found in fully induced mutant cells. After growth in minimal glycerol medium there is a significant reduction in wild-type cells of the activities of both pyruvate dehydrogenase and dihydrolipoyl transacetylase. This evidence indicates a relationship between the conditional acetate requirement by wild-type cells grown on glycerol medium and the levels of the pyruvate dehydrogenase complex.     

Enhancers of Glp-1, a Gene Required for Cell-Signaling in Caenorhabditis Elegans, Define a Set of Genes Required for Germline Development

The distal tip cell (DTC) regulates the proliferation or differentiation choice in the Caenorhabditis elegans germline by an inductive mechanism. Cell signaling requires a putative receptor in the germline, encoded by the glp-1 gene, and a putative signal from the DTC, encoded by the lag-2 gene. Both glp-1 and lag-2 belong to multigene gene families whose members are essential for cell signaling during development of various tissues in insects and vertebrates as well as C. elegans. Relatively little is known about how these pathways regulate cell fate choice. To identify additional genes involved in the glp-1 signaling pathway, we carried out screens for genetic enhancers of glp-1. We recovered mutations in five new genes, named ego (enhancer of glp-1), and two previously identified genes, lag-1 and glp-4, that strongly enhance a weak glp-1 loss-of-function phenotype in the germline. Ego mutations cause multiple phenotypes consistent with the idea that gene activity is required for more than one aspect of germline and, in some cases, somatic development. Based on genetic experiments, glp-1 appears to act upstream of ego-1 and ego-3. We discuss the possible functional relationships among these genes in light of their phenotypes and interactions with glp-1.     

Automatic luminometric kinetic assay of glycerol for lipolysis studies

A kinetic assay for glycerol based on the glycerokinase and firefly luciferin-luciferase reactions was developed for the purpose of allowing automatic analysis of large series of incubates from human fat cells. The method includes simplified sampled pretreatment and fully automated analysis, recording, and calculation of data. The upper limit of the dynamic range of the assay was extended from a glycerol concentration in cuvette of 2 up to 100 microM. This is due to a principally new method to linearize the nonlinear part of the standard curve. Recovery experiments reveal 100% glycerol recovery. Within-run and between-run precisions are high with coefficients of variation of between 1.2 and 3.7%. Samples are stable for up to 6 months in an ordinary freezer. The detection limit expressed as 2 SD of the blank result is 0.07 microM glycerol in cuvette, which is slightly lower when compared to the previous luminometric methods. The apparent blank, which is typically 0.4-1.0 microM glycerol in cuvette, has shown significant contributions only from bovine serum albumin, 0.03 microM, and glycerokinase, 0.01 microM. The analytical performance and degree of automation of the glycerol method described in this paper makes it well suited for serial studies of lipolysis in human fat cells in the presence of lipolytic or antilipolytic agents.     

Method for triglyceride measurement in small amounts of plasma

A method is described for determining triacylglyceride concentration in small amounts of plasma. After ethanolic-KOH digestion of diluted plasma aliquots, samples were neutralized with MgSO4 and glycerol was fluorimetrically assayed in supernatants by the coupling of glycerokinase, pyruvate kinase, and lactate dehydrogenase catalyzed reactions. Values were corrected by free glycerol present in the non-digested samples. Digestions were performed at different times and temperatures in order to establish optimum conditions for recoveries and reproducibility. Parallel determinations before and after phospholipid removal showed that their presence in plasma did not interfere with the obtained values. This method is especially useful for running many samples in parallel and for determinations in small experimental animals in which the amount of plasma is very limited.     

The inhibition of glucokinase and glycerokinase from Bacillus stearothermophilus by the triazine dye Procion Blue MX-3G.

Glucokinase from Bacillus stearothermophilus was irreversibly inactivated by the reactive dichlorotriazinyl dye Procion Blue MX-3G at pH 8.0. The enzyme was protected from inactivation by the substrate MgATP. Kinetic data implied that the dye occupied the MgATP-binding site. The apparent Km values for MgATP and D-glucose were found to be 70 microM and 210 microM respectively, and the Kd of the pure reactive dye was 16 microM; 1 mol of the pure reactive dye bound to 1 mol of glucokinase subunit. The dye was shown to have potential as an affinity probe for glucokinase. Glycerokinase from the same bacterium was inactivated by Procion Blue MX-3G at high concentrations (5 mM), but only after a period of increased enzyme activity. Kinetic data indicated that the dye preferentially attacked the glycerol-binding site. The apparent Km values for MgATP and glycerol were found to be 38 microM and 13 microM respectively, and 4 mol of reactive dye could be bound to 1 mol of glycerokinase subunit. This was surprising in view of the MgATP-dependent elution of glycerokinase from immobilized Procion Blue MX-3G.     

Differential rates of synthesis of glycerokinase and glycerophosphate dehydrogenase in Neurospora crassa during induction.

The synthesis of the enzymes of the glycerophosphate pathway in Neurospora has been examined during exponential growth of cells on acetate as the sole carbon source. After the addition of glycerol to the media, increases in the levels of both glycerokinase and a mitochondrial glycerol-3-phosphate dehydrogenase are observed within 1 h and fully induced levels are reached within one and a half mass doublings for glycerokinase and two and a half mass doublings for glycerol-3-phosphate dehydrogenase. The increase in glycerokinase activity represents de novo synthesis of enzyme as evidenced by the absence of immunologically related protein in uninduced cell extracts. The synthesis of both glycerokinase and glycerol-3-phosphate dehydrogenase can be totally inhibited by treatment of cells with 20 μg/ml cycloheximide. During incubation with 4 mg/ml chloramphenicol, there is normal synthesis of glycerokinase but a 30–50% inhibition of mitochondrial glycerol-3-phosphate dehydrogenase synthesis. However, under these conditions, in the cytosol fraction there is a significant increase in glycerol-3-phosphate dehydrogenase specific activity, suggesting that precursors are synthesized and accumulated in the cytosol prior to incorporation into mitochondria. Upon removal of chloramphenicol, the rate of appearance of glycerol-3-phosphate dehydrogenase into the mitochondria is up to four times greater than observed in untreated controls. It is concluded that both glycerokinase and glycerol-3-phosphate dehydrogenase are synthesized on cytoplasmic ribosomes, but that final assembly of glycerol-3-phosphate dehydrogenase into mitochondria is dependent on concomitant synthesis of mitochondrial inner membrane.     

Isolation and characterization of salt-sensitive mutants of a salt-tolerant yeast Zygosaccharomyces rouxii

Abstract Twenty salt-sensitive (ss) mutants were isolated from the salt-tolerant yeast Zygosaccharomyces rouxii by treatment with N -methyl- N '-nitro- N -nitrosoguanidine. The mutants were divided into five classes on the basis of their ability to grow in media containing various high concentrations of NaCl. The mutant with the greatest sensitivity to NaCl of all the mutants tested was able to grow very slowly with a longer lag phase in medium containing 2 M NaCl, in contrast to the wild strain which had the capacity to grow in medium containing 3.5 M NaCl. Most of the ss mutants exhibited, to some extent, less tolerance to high concentrations of glucose than the wild strain. It appeared from the characterization of the ss mutants that the following factors are necessary for growth of Z. rouxii in high concentrations of NaCl: (a) the ability to produce glycerol under these conditions; (b) the ability to maintain a defined concentration of glycerol within the cells; (c) the ability to take up glycerol that has leaked into the medium, and to assimilate glycerol; and (d) unknown factor(s).     

Flow-injection enzymatic analysis for glycerol and triacylglycerol

A flow-injection enzymatic analytical system was developed for determination of glycerol and triacylglycerol based on enzymatic reactions in capillary followed by electrochemical detection. The hydrogen peroxide produced from the enzyme reaction was monitored by a platinum-based electrochemical probe. Different immobilization strategies on silica support were studied. The best and most effective configuration found for the measurement of glycerol and triacylglycerols in this system was the tandem connection of a lipase column and a silica-fused capillary column coimmobilized with glycerokinase (GK) and glycerol-3-phosphate oxidase (GPO). Lipase helps the breakdown of triacylglycerol to yield free fatty acids and glycerol, while glycerokinase catalyzes the adenosine-5-triphosphate-dependent phosphorylation of glycerol to yield alpha-glycerol phosphate, which can subsequently be oxidized by 3-glycerol phosphate oxidase to produce hydrogen peroxide. Response-surface methodology (RSM) was applied to optimize the proposed system for glycerol. Experiment settings were designed by central composite design to investigate the combined effects of pH, flow rate, reaction temperature, and ATP concentration on collected signals. The fitted model, per RSM, showed that the optimum conditions of the system are 2 mM ATP in 0.1 M carbonate buffer (pH 11.0), flow rate of 0.18 mL/min, temperature of 35 degrees C, 20 microL of sample injection, and applied voltage of 0.650 V. The proposed biosensing system using lipase, GK, and GPO exhibited a flow-injection analysis peak response of 2.5 min and a detection limit of 5 x 10(-5) M glycerol (S/N = 3) with acceptable reproducibility (CV < 4.30%). It also had linear working ranges from 10(-4) to 10(-2) M for glycerol and from 10(-3) to 10(-2) M for triacylglycerol. The capillary enzyme reactor was stable up to 2 months in continuous operation, and it was possible to analyze up to 15 samples per hour. The present biosensing system holds promise for on-line detection of triacylglycerol in serum and glycerol content in fermented products.     

Radiometric assays for glycerol, glucose, and glycogen

We have developed radiometric assays for small quantities of glycerol, glucose and glycogen, based on a technique described by Thorner and Paulus (1971, J. Biol. Chem. 246, 3885-3894) for the measurement of glycerokinase activity. In the glycerol assay, glycerol is phosphorylated with [32P]ATP and glycerokinase, residual [32P]ATP is hydrolyzed by heating in acid, and free [32P]phosphate is removed by precipitation with ammonium molybdate and triethylamine. Standard dose-response curves were linear from 50 to 3000 pmol glycerol with less than 3% SD in triplicate measurements. Of the substances tested for interference, only dihydroxyacetone gave a slight false positive signal at high concentration. When used to measure glycerol concentrations in serum and in media from incubated adipose tissue, the radiometric glycerol assay correlated well with a commonly used spectrophotometric assay. The radiometric glucose assay is similar to the glycerol assay, except that glucokinase is used instead of glycerokinase. Dose response was linear from 5 to 3000 pmol glucose with less than 3% SD in triplicate measurements. Glucosamine and N-acetylglucosamine gave false positive signals when equimolar to glucose. When glucose concentrations in serum were measured, the radiometric glucose assay agreed well with hexokinase/glucose-6-phosphate dehydrogenase (H/GDH)-based and glucose oxidase/H2O2-based glucose assays. The radiometric method for glycogen measurement incorporates previously described isolation and digestion techniques, followed by the radiometric assay of free glucose. When used to measure glycogen in mouse epididymal fat pads, the radiometric glycogen assay correlated well with the H/GDH-based glycogen assay. All three radiometric assays offer several practical advantages over spectral assays.     

Glyceroneogenesis and the supply of glycerol-3-phosphate for glyceride-glycerol synthesis in liver slices of fasted and diabetic rats

The pathways of glycerol-3-phosphate (G3P) generation for glyceride synthesis were examined in precision-cut liver slices of fasted and diabetic rats. The incorporation of 5 mM [U-(14)C]glucose into glyceride-glycerol, used to evaluate G3P generation via glycolysis, was reduced by approximately 26-36% in liver slices of fasted and diabetic rats. The glycolytic flux was reduced by approximately 60% in both groups. The incorporation of 1.0 mM [2-(14)C]pyruvate into glyceride-glycerol (glyceroneogenesis) increased approximately 50% and approximately 36% in slices of fasted and diabetic rats, respectively, which also showed a two-fold increase in the activity phosphoenolpyruvate carboxykinase. The increased incorporation of 1.0 mM [2-(14)C]pyruvate into glyceride-glycerol by slices of fasted rats was not affected by the addition of 5 mM glucose to the incubation medium. The activity of glycerokinase and the incorporation of 1 mM [U-(14)C]glycerol into glyceride-glycerol, evaluators of G3P formation by direct glycerol phosphorylation, did not differ significantly from controls in slices of the two experimental groups. Rates of incorporation of 1 mM [2-(14)C]pyruvate and [U-(14)C]glycerol into glucose of incubation medium (gluconeogenesis) were approximately 140 and approximately 20% higher in fasted and diabetic slices than in control slices. It could be estimated that glyceroneogenesis by liver slices of fasted rats contributed with approximately 20% of G3P generated for glyceride-glycerol synthesis, the glycolytic pathway with approximately 5%, and direct phosphorylation of glycerol by glycerokinase with approximately 75%. Pyruvate contributed with 54% and glycerol with 46% of gluconeogenesis. The present data indicate that glyceroneogenesis has a significant participation in the generation of G3P needed for the increased glyceride-glycerol synthesis in liver during fasting and diabetes.     

Mutants of Pichia guilliermondii yeasts with multiple sensitivity to antibiotics and antimetabolites. I. The selection and properties of the mutants

Riboflavin deficient mutant Pichia guilliermondii MS1 which requires approximately 1000-fold lower concentration of exogenous vitamin B2 for growth when compared with a non-adapted riboflavin deficient mutants of this species was isolated by means of of UV-irradiation. The growth of the mutant was strongly inhibited by actinomycin D and L-canavanine. The revertant MS8 and MS14 which synthesized riboflavin were selected from the strain MS1. These revertants posses a multiple sensitivity to actinomycin D, rifamycin, euflavine, mitomycin C, antimycin A, 8-azaadenine, 8-azaguanine, L-canavanine and 7-methyl-8-trifluoromethyl-10-(1'-D-ribityl)isoalloxazine. The ability to utilized glycerol and ethanol as a sole carbon source for growth was impaired in these mutants. The mutants which can utilize glycerol were isolated from the strain MS14. Such mutants were resistant to actonomycin D. Mutation (s) which determines a multiple sensitivity and inability to utilized glycerol was recessive.     

Relationship between catabolism of glycerol and metabolism of hexosephosphate derivatives by Pseudomonas aeruginosa.

The relationship between catabolism of glycerol and metabolism of hexosephosphate derivatives in Pseudomonas aeruginosa was studied by comparing the growth on glycerol and enzymatic constitution of strain PAO with these characteristics of glucose-catabolic mutants and revertants. Growth of strain PAO on glycerol induced a catabolic oxidized nicotinamide adenine dinucleotide-linked glyceraldehyde-phosphate dehydrogenase and seven glucose-catabolic enzymes. The results indicated that these enzymes were induced by a six-carbon metabolite of glucose. All strains possessed a constitutive anabolic Embden-Meyerhof-Parnas pathway allowing limited conversion of glycerol-derived triosephosphate to hexosephosphate derivatives, which was consistent with induction of these enzymes by glycerol. Phosphogluconate dehydratase-deficient mutants grew on glycerol. However, mutants lacking both phosphogluconate dehydrogenase and phosphogluconate dehydratase were unable to grow on glycerol, although these strains possessed all of the enzymes needed for degradation of glycerol. These mutants apparently were inhibited by hexosephosphate derivatives, which originated from glycerol-derived triosephosphate and could not be dissimilated. This conclusion was supported by the fact that revertants regaining only a limited capacity to degrade 6-phosphogluconate were glycerol positive but remained glucose negative.     

Changes in enzyme systems and lipogenesis metabolites in experimental tuberculosis

Lung tissue phospholipid metabolism has been studied under the conditions of experimental tuberculosis. These investigations were combined with the simultaneous studying of the qualitative and quantitative composition of individual phospholipids, of the changes in the content of glycerophosphate and dioxiacetonphosphate, as well as, of the abnormalities in the activity of glycerokinase and glycerophosphatedehydrogenase, which play an important role in the catalysis of the initial processes of phosphatidogenesis. Our data obtained have shown that formation of tuberculosis process is accompanied by the pronounced increase of glycerokinase and glycerophosphatedehydrogenase activities, which leads to the significant accumulation of the dioxiacetonphosphate and the free glycerol concentrations. It was established by us, that under the conditions of the pathology studied, the significant decrease of the quantity of phosphatidylcholines, phosphatidylethanolamines and phosphatidylserines took place, while the level of sphingomyelins was increased. The results of our investigations shed the light on the up-to-date understanding of the role of different fractions of phospholipids, as well as, of corresponding enzymatic systems in the pathogenesis of lung tuberculosis and in the formation of focus of necrosis in lung tissue.