Multiple forms

Isolation of multiple forms of Periphylla luciferase. In agreement with the histological findings noted above, two types of luciferase, a... 

Blinks, J. R., and Harrer, G. C. (1975). Multiple forms of the calcium-sensitive bioluminescent protein aequorin. Fed. Proc. 34 474. 

MotoyamaN, Dauterman WC. 1978. Multiple forms of rat liver glutathione S-transferases Specificity for conjugation of 0-alkyl and 0-aryl groups of organophosphorus insecticides. J Agr Food Chem 26 1296-1301. 

Hirschfield, I.N., Bloch, P.L., Van Bogelen, R.A. Neidhardt, F.C. (1981). Multiple forms of lysyl-transfer ribonucleic acid synthetase in Escherichia coli. Journal of Bacteriology, 146, 345-51. 

As might be expected, mRNA for the 5-HT transporter is found in high concentrations in the Raphe nuclei but it is also found in other brain regions. Whether this means that non-5-HT neurons can synthesise this protein is unknown but there is some evidence that it is synthesised in astrocytes, at least. One complication is that there are multiple forms of mRNA for the 5-HT transporter, but there is, as yet, no evidence for transporter subtypes in the CNS. However, it must also be remembered that 5-HT transporters are found in the peripheral tissues, notably platelets, mast cells, the placental brush-border and adrenal chromaffin cells and it is possible that these are not all identical. 

Pressey,R and Avants,J.K (1972) Multiple forms of pectinesterases in tomatoes. Phytochemistry. 11. 3139-3142. 

Evans, R. McHale, D. 1968. Multiple forms of pectinesterase in limes and oranges. Phytochemistry 17 1073-1075. 

Although the first study of exopolygalacturonases from carrots [11] indicated the presence of multiple forms of this enzyme based on the three present pH optima, the latter studies supported the idea of one form of exopolygalacturonase [2-4]. The present study deals with the whole spectrum of multiple forms of exopolygalacturonase, with forms described sooner and with forms found only now. 

This work should be considered as an introduction to plant exopolygalacturonase multiple forms structure studies. 

Candida boidinii is a further yeast producer of pectic enzymes complex. The production is induced by the presence of pectin as a C-source in the medium the primary methabolic path is the utilization of methanol and the secondary the utilization of pectate chains. The pectic enzymes were bound on the cell walls or released on the cultivation medium. The main enzyme of pectic complex, polygalacturonase, was briefly characterized and the possibility to influence the production of its multiple forms discussed. 

The activity of the main enzyme of pectic enzymes complex, polygalacturonase, was dependent on the pH of the cultivation media the highest activity was reached at pH 3.51 (natural pH of pectin medium), the activity decreased to 70% and 20% by the cultivation at pH 5.49 and pH 7.01, respectively. The isoelectric focusing patterns showed the production of polygalacturonase multiple forms with isoelectric points varying from 3.5 to 7.5 (Fig. 3 A,B) with the possibility to influence their production with the change of the C-source and pH of the cultivation media. 

Fig. 3. Isoelectric focusing in ultrathin polyacrylamide layers (pH gradient 3 -10) of multiple forms of polygalacturonase produced by Candida boidinii under different cultivation conditions a - pectin, pH 3.51 b - pectin, pH 5.49 c -pectin, pH 7.01 d - 20% of D-galactopyranuronic acid in pectin e - pectate. A - Activity detection with print technique on colouress D-galacturonan DP 10 dyed additionally with ruthenium red ( both exo- and polygalacturonases) and B - activity detection with Ostazin Brilliant Red/D-galacturonan DP 10 agar print (polygalacturonases).

Triose phosphate isomerase (TPI) catalyzes the interconversion of glyceralde-hyde-3-phosphate and dihydoxyacetone phosphate and has an important role in glycolysis, gluconeogenesis, fatty acid synthesis, and the hexose monophosphate pathway. Red blood cell TPI activity measured in vitro is approximately 1000 times that of Hx, the least active glycolytic enzyme. TPI is a dimer of identical subunits, each of molecular weight 27,000, and does not utilize cofactors or metal ions. Posttranslational modification of one or both subunits may occur by deamidination, resulting in multiple forms of the enzymes and creating a complex multibanded pattern on electrophoresis. 

C. Multiple Forms of the Rapid Signal and their Origins. 123... 

Wong, P, Ulyanova, T, Organisciak, DT, Bennett, S, Lakins, J, Arnold, JM, Kutty, RK, Tenniswood, M, van Veen, T, Darrow, RM, and Chader, G, 2001. Expression of multiple forms of clusterin during light-induced retinal degeneration. Curr Eye Res 23, 157-165. 

Fungal laccases (benzenediokoxygen oxidoreductase, EC 1.10.3.2) belong to the multicopper blue phenoloxidases. They comprise glycosylated proteins expressed in multiple forms and variable molecular weight, ranging from 59 to 110 kDa. Laccase is expressed as multiple constitutive and induced isoenzymes [30, 64]. The enzyme contains four copper atoms (Cu), in different states of oxidation (I, II, III) [65], which play an important role in the catalytic mechanism. Laccase oxidizes different compounds while reducing O2 to H20, a total reduction of four electrons. 

By means of gel electrophoresis on cross-linked, hydrolyzed starch,99 with simultaneous checking for proteins, lipids, and pectinesterase activity, it was found, however, that the product isolated after the separation on CM-Sephadex C-50 constitutes but one of five multiple forms of tomato pectinesterase, and is the one present in preponderant proportion98 (see Fig. 4). The accompanying lipid and sugar components were separated from this pectinesterase form in the course of the purification procedure. After analysis of the hydro-lyzate of the final product for fatty acids, as well as for carbohydrate components, it was possible to exclude the possibility of a lipoprotein,30 as well as glycoprotein,100 character of this form of tomato pectinesterase. 

By use of starch-gel electrophoresis, the total extract of bananas, and the fractions obtained after separation on DEAE-Sephadex A-50, were found to contain six multiple forms of pectinesterase having electrophoretic patterns different from those of tomato pectinesterase.103... 

Primarily nonneuronal, multiple forms, widespread distribution Widespread distribution, enriched at MTOC, severs MT Widespread distribution, destabilizes MT... 

Luduena, R. F. Multiple forms of tubulin different gene products and covalent modifications. Int. Rev. Cytol. 178 207-275,1998. 

Multiple forms of heterotrimeric G proteins exist in the nervous system 336... 

Multiple forms of heterotrimeric G proteins exist in the nervous system. Three types of heterotrimeric G protein were identified in early studies. G termed transducin, was identified as the G protein that couples rhodopsin to regulation of photoreceptor cell function (see Ch. 49), and Gs and G were identified as the G proteins that couple plasma membrane receptors to the stimulation and inhibition, respectively, of adenylyl cyclase, the enzyme that catalyzes the synthesis of cAMP (see Ch. 21). 

As a second messenger, DAG is rapidly metabolized under normal conditions, and the predominant route is via phosphorylation to PA, a reaction catalyzed by DAG kinase, for which multiple forms of 64-140 kDa have been identified and characterized. All possess a C-terminal catalytic domain and two or three cysteine-rich repeat sequences. The a, 3 and y forms possess E-F hands and are thus likely to be regulated by changes in the concentration of cytosolic Ca2+. Expression of the mRNA for the a, P, y, C, and 0 forms of DAG kinase appears to be highest in the brain. Once DAG is phosphorylated to PA, this in turn can be converted into PI via CDP-DAG (Fig. 20-2B). 

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