Cytoplasmic fraction

Figure 2. PemB cellular localisation. (A) Fractionation of E. chrysanthemi cells by spheroplasting. Lane 1, culture supernatant lane 2, total cell lysate lane 3, periplasmic fraction lane 4, crude membrane fraction lane 5, cytoplasmic fraction. (B) Detergent extraction of PemB from E. chrysanthemi A837 cell envelopes. Lane 1 crude envelope fraction lane 2 Triton-soluble fraction lane 3 Triton-insoluble fraction lane 4 Sarkosyl-soluble fraction lane 5 Sarkosyl-insoluble fraction.

Histamine synthesis in the brain is controlled by the availability of L-histidine and the activity of histidine decarboxylase. Although histamine is present in plasma, it does not penetrate the blood-brain barrier, such that histamine concentrations in the brain must be maintained by synthesis. With a value of 0.1 mmol/1 for L-histidine under physiological conditions, HDC is not saturated by histidine concentrations in the brain, an observation that explains the effectiveness of large systemic doses of this amino acid in raising the concentrations of histamine in the brain. The essential amino acid L-histidine is transported into the brain by a saturable, energy-dependent mechanism [5]. Subcellular fractionation studies show HDC to be localized in cytoplasmic fractions of isolated nerve terminals, i.e. synaptosomes. 

In mouse liver and kidney and in rat liver, a-D-mannosidase activity appeared to be equally distributed between the two cytoplasmic-granule fractions. With mouse spleen and cancer tissue, a considerable proportion of the enzyme was found free in the cytoplasm. Rat spleen, on the other hand, lacked this cytoplasmic fraction. Inasmuch as the enzyme within the cytoplasmic granules was not fully active in a sucrose homogenate until the membranes had been disintegrated, a-D-mannosidase conforms to the definition of a lysosomal hydrolase. 

A novel cytochrome b model compound containing two heme binding sites was tested by EPR and Mossbauer spectroscopy. Both sites were found to be occupied in a 1 1 stoichiometry. For one of the sites a normal b-hemichrome EPR signal with rhombic -tensor symmetry was found as expected for a bis-histidine ligation with parallel histidine planes. For the other site unusual EPR features (e.g. axial y-tensor) were obtained which were ascribed to a configuration with perpendicular histidine planes.267 A new type of cytochrome b was described for a preparation from the cytoplasmic fraction of an archaeon, Acidianus ambivalens. This is thus the first soluble cytochrome found in this... 

AMP aminohydrolase, an enzyme relatively specific for AMP, has been observed in reptiles (44), erythrocytes (38), snail (45), unfertilized fish eggs (46), invertebrates (47), a variety of mammalian tissues (20), and a particulate fraction of pea seeds (48). Evidence suggests that the frog muscle AMP aminohydrolase is located within or just beneath the sarcolemma (49). The rabbit skeletal and heart muscle enzymes were found in the cytoplasm and mitochondria (20, Jfi, 50, 51), while the enzyme of kidneys and gills of freshwater fish was located in the cytoplasmic fraction (52). The enzyme occurs in most areas of the rat (53) and rabbit brain (54). The nonspecific enzyme from several microbial sources deaminates adenosine triphosphate (ATP) and adenosine diphosphate (ADP) as well as AMP (see Section V). 

A functional uricase was obtained by expression in E. coli of a soybean N-35 cDNA driven by the bacterial lacZ promoter (Suzuki Verma, 1991). The uricase activity was mainly found in the cytoplasmic fraction of E. coli and had the same pH optimum and apparent Km values as in the nodules. That N-35 is able to assemble into a functional, tetrameric holoenzyme in E. coli indicates that post-translational modifications, or the presence of peroxisomes, is not essential for its proper assembly and function in this organism. However, N-35 is not active and does not accumulate to any significant levels when it is expressed in transgenic tobacco under the control of the CaMV-35S promoter (our unpublished data). 

Phosphorylase activity in spinach leaf is also distributed in the chloroplastic and cytoplasmic fractions, but in comparable amounts.46,47 The cytoplasmic enzyme has much higher affinity for... 

To evaluate the possibility of postexponential cell wall synthesis occurring without protein synthesis, we disrupted bacteria by shaking with glass beads. Under proper conditions this yields a water-soluble and a water-insoluble fraction. As a first approximation the soluble fraction may be called the cytoplasmic fraction and the insoluble part the wall fraction. Figure 4 shows a study by the glass bead procedure of cells from the exponential growth phase and of 20-hour cells result-... 

The contractile proteins of the myofibril include three troponin regulatory proteins. The troponin complex includes three protein subunits, troponin C (the calcium-binding component), troponin I (the inhibitory component), and troponin T (the tropomyosin-binding component). The subunits exist in a number of isoforms. The distribution of these isoforms varies between cardiac muscle and slow- and fast-twitch skeletal muscle. Only two major isoforms of troponin C are found in human heart and skeletal muscle. These are characteristic of slow- and fast-twitch skeletal muscle. The heart isoform is identical with the slow-twitch skeletal muscle isoform. Isoforms of cardiac-specific troponin T (cTnT) and cTnl also have been identified and are the products of unique genes. All cardiac troponins are localized primarily in the myofibrils (94%-97%), with a smaller cytoplasm fraction (3%-6%). 

According to many of the researchers, one of the AD risks is an elevated cholesterol level [98-100]. It should be noted that the cholesterol content in rat brain tissues decreased by 40% within 2 h after introduction of 15 mg/kg of the compound to the animals. The eholesterol content in a cytoplasmic fraction isolated from miee brain decreased almost two-fold within 2.5 h after introduction of 6 mg/kg of ichfan. 

Collect 200-250 pi of the turbid upper layer (cytoplasmic fraction) and add 1/2 volume of proteinase K solution. Incubate at 37°C for 30 min, extract with phenol/chloroform twice, and precipitate with ethanol. ... 

The transmitter that is taken up into the neuron and liberated into the intracellular fluid can then either be recycled into vesicular storage granules or metabolized by intracellular enzymes. The two enzymes that are of major importance for the catabolism of aromatic monoamines are monoamine oxidase, of which there may be two or more isozymes, and catechol-O-meth-yltransferase. In neurons, monoamine oxidase is associated with mitochondria, whereas catechol-O-methyltransferase is associated with the soluble cytoplasmic fraction. Both monoamine oxidase and catechol-O-methyltransferase can act on monoamines sequentially to form a variety of metabolic products. These have been identified by radioisotopic and chromatographic experiments. The major metabolites of the aromatic monoamines have been identified 3-methoxy-4-hydroxyphenylethylene glycol and 3-methoxy-4-hydroxymandelic acid (vanylmandelic acid) for norepinephrine and epinephrine 3,4-dihydroxyphenylacetic acid and 3-meth-... 

Dyctyoglomus thermophilum Rt46B.l,73] 90 5.5 75 Purified/cloned/cytoplasmic fraction... 

Figure 3 Expression of a ferulic acid esterase from N. crassa in E. coli. Cells were grown at 38°C and induced at ODb00 — 0.4 with 0.4 mM IPTG. C control strain transformed with pET3a. P protein expression strain transformed with pET3afizs-. Pperi periplasmic fraction. Pcyto cytoplasmic fraction. Pmemb membrane and inclusion bodies fraction. M standard protein molecular weight. — pre-induction. + post-induction...

Result in increased smooth endoplasmic reticulum Result in increased rough endoplasmic reticulum Result in decreased enzymes in the soluble cytoplasmic fraction Require 3 months to reach completion Be irreversible... 

The transfer of a sulfonate group from the donor compound 3 -phosphoadenosine 5 -phosphosulfate (PAPS) to an acceptor compound (such as TH, steroids,. .. but also xenobiotics) is catalyzed by a large family of enzymes called sulfotransferases, located in the cytoplasmic fraction of, e.g., liver cells. Unlike glucuronidation, sulfation does not facilitate the excretion ofTH, but interferes with the deio-dination process. Sulfated THs strongly facilitate the IRD activity of D1 while they inhibit the D2, D3 activity, and theORDofDl Moreno et al., 1994 VisserT. J., 1990). 

Cytoplasmic Peptidophosphogalactomannan. Fungal peptido-galactomannans have been extracted from powdered preparations (43). However, we were unable to obtain phosphogalactomannan from the cell walls of 3-day cultures of charlesii (20). When we examined extracts of P. charlesii cells we found galactofurano-syl residues both in a soluble cytoplasmic and a membrane-bound cytoplasmic fraction. 

Several biochemical studies into the effects of novobiocin on membrane synthesis have been carried out. For example, the incorporation of radioactive glucose into the mannose fractions of the cytoplasmic membrane of M. lysodeikticus has been found to be inhibited by novobiocin [31], although similar inhibitions occur in other cellular fractions. With the use of protoplasts of B. megaterium, it has been shown [67] that the incorporation of radioactive amino acids and glycerol into both membrane and cytoplasmic fractions is inhibited by similar degrees. It was concluded that, although the membrane may be malfunctional, the cytoplasmic structure of novobiocin-treated protoplasts can be similarly described. 

---