Metal and metalliod amides (Lappert, M. F.; Power, P. P., Sanger, A. R., Srivastava R. C.)

Abstract

Sons., New York. 1980. xiv + 436 pp. Figs. and tables. 15.5 X 24 cm.Harald Giinther has produced an outstanding text on nuclear magnetic resonance spectroscopy in the tradition of those by Recker and hy Bovey. Although the titular purpose of the book is introductory. the author very adroitly treats concepts and techniques that are both modern and snphistieated. The hmk emphasizes proton NMR spectroscopy. About 1070 of the total is addressed specifically to two other nuclei.fluorine-19 and carhon-13.

Muscle as the Primary Site of Urea Cycle Enzyme Activity in an Alkaline Lake-adapted Tilapia, Oreochromis alcalicus grahami

“…Similar results are obtained at 1 mM MgATP, except that the K m for ammonia in the absence of AGA is lower (1.8 mM). The K m values of 2-5 mM for ammonia are comparable with those observed for the ammonia-dependent activity of other type III (21,22) and type I (23) CPSases. Like the ureoosmotic spiny dogfish shark (Squalus acanthias, a representative ureoosmotic elasmobranch) CPSase III (21) and type I CPSases (23), however, AGA does affect MgATP binding and, therefore, activity at physiological concentrations of ATP.…”

“…In other type III CPSases: 1) the V max with ammonia as substrate is 10% or less than the V max with glutamine as substrate, 2) AGA under normal assay conditions is required for activity, 3) the binding of glutamine and AGA are synergistic (i.e. as the concentration of one is increased, the K m for the other decreases), and 4) the K m for glutamine is 0.1-0.2 mM (21,22). In contrast, for the tilapia CPSase III assayed with 20 mM MgATP: 1) the V max with ammonia as substrate is greater than the V max with glutamine, 2) AGA is not required for activity with either ammonia or glutamine as nitrogen-donating substrate and the presence of AGA increases V max only slightly, 3) AGA does not affect the apparent K m for glutamine (or ammonia), and 4) the K m for glutamine is quite high.…”

“…The open reading frame codes for 1,535 amino acid residues, the first 37 of which correspond to an expected mitochondrial signal sequence which, when removed, would yield a mature protein with the N-terminal sequence FSVKTQTAHL; the sequence also has the expected cysteine residues required for activity with glutamine (Cys-298) and binding of AGA (Cys-1352 and Cys-1362) (6). CPSase III from shark and smallmouth bass have turnover rates of Ϸ0.2 mol/min/mg of protein at 26°C with glutamine as substrate (21,22). If the turnover rate of the tilapia CPSase III is similar, the presence of 0.2 unit of activity/g of muscle would correspond to Ϸ1 mg of CPSase/g of muscle, which should be detectable in crude extracts by SDS-PAGE.…”

Effects of Oxygen Additions to Argon Shielding Gas on GTA Weld Shape

“…Minor elements can be added to the weld pool by adjusting the chemical composition to the base material, [1][2][3][4][5][6] smearing fluxes (halides or oxides) on the plate surface [7][8][9][10][11][12][13][14][15][16][17][18][19] or using active gaseous addition to the argon shielding gas. [20][21][22] The intentional or unintentional addition of a small amount of minor elements to the base material significantly changes the weld penetration.…”

Expression of Carbamoyl-phosphate Synthetase III mRNA during the Early Stages of Development and in Muscle of Adult Rainbow Trout (Oncorhynchus mykiss)

“…The properties and function of CPSase III are very much like those of the urea cycle-related CPSase I, except that glutamine is utilized as the nitrogen-donating substrate instead of ammonia (9,19). The sequence of the CPSase III cDNA from spiny dogfish shark (a representative elasmobranch) has been reported and is homologous to other CPSases, sharing highest similarity in amino acid sequence to rat, human, and frog CPSase I (70 -75% identity) and less to CPSase IIs (about 50% identity) (20).…”