Hydrolysis of Zirconium and Hafnium Siloxide Complexes. Isolation and Characterization of the Intermediate Aqua Complexes M[OSi(OtBu)3]4(H2O)n(M = Zr, Hf;n= 1, 2)

1998 ◽  
Vol 37 (4) ◽  
pp. 764-769 ◽  
Author(s):  
Claus G. Lugmair ◽  
T. Don Tilley
Keyword(s):  
Aqua Complexes ◽  
Isolation And Characterization ◽  
Hydrolysis Of

Isolation and characterization of anti-inflammatory peptides derived from trypsin hydrolysis of microalgae protein (Synechococcus sp. VDW)

2019 ◽  
Vol 33 (4) ◽  
pp. 303-324 ◽  
Author(s):  
Rutairat Suttisuwan ◽  
Saranya Phunpruch ◽  
Tanatorn Saisavoey ◽  
Papassara Sangtanoo ◽  
Nuttha Thongchul ◽  
...  
Keyword(s):  
Isolation And Characterization ◽  
Trypsin Hydrolysis ◽  
Synechococcus Sp ◽  
Anti Inflammatory ◽  
Hydrolysis Of

scholarly journals Isolation and characterization of a γ-type phosphoinositide-specific phospholipase C (PLC-γ2)

1990 ◽  
Vol 269 (1) ◽  
pp. 13-18 ◽  
Author(s):  
Y Homma ◽  
Y Emori ◽  
F Shibasaki ◽  
K Suzuki ◽  
T Takenawa
Keyword(s):  
Phospholipase C ◽  
Column Chromatography ◽  
Specific Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Deae Cellulose ◽  
Isolation And Characterization ◽  
Delta Type ◽  
Hydrolysis Of ◽  
Cellulose Column

A novel bovine spleen phosphoinositide-specific phospholipase C (PLC) has been identified with respect to immunoreactivity with four independent antibodies against each of the PLC isoenzymes, and purified to near homogeneity by sequential column chromatography. Spleen contains three of the isoenzymes: two different gamma-types [gamma 1 and gamma 2, originally named as PLC-gamma [Rhee, Suh, Ryu & Lee (1989) Science 244, 546-550] and PLC-IV [Emori, Homma, Sorimachi, Kawasaki, Nakanishi, Suzuki & Takenawa (1989) J. Biol. Chem. 264, 21885-21890] respectively] and delta-type of the enzyme, but PLC-gamma 1 is separated from the PLC-gamma 2 pool by the first DEAE-cellulose column chromatography. Subsequently, PLC-delta is dissociated on the third heparin-Sepharose column chromatography. The purified enzyme has a molecular mass of 145 kDa on SDS/polyacrylamide-gel electrophoresis and a specific activity of 12.8 mumol/min per mg with phosphatidylinositol 4,5-bisphosphate as substrate. This enzyme activity is dependent on Ca2+ for hydrolysis of all these phosphoinositides. None of the other phospholipids examined could be its substrate at any concentration of Ca2+. The optimal pH of the enzyme is slightly acidic (pH 5.0-6.5).

scholarly journals Ectoenzymes of the kidney microvillar membrane. Isolation and characterization of the amphipathic form of renal dipeptidase and hydrolysis of its glycosyl-phosphatidylinositol anchor by an activity in plasma

1989 ◽  
Vol 261 (3) ◽  
pp. 811-818 ◽  
Author(s):  
N M Hooper ◽  
A J Turner
Keyword(s):  
Membrane Anchor ◽  
Glycosyl Phosphatidylinositol ◽  
Isolation And Characterization ◽  
C Terminus ◽  
Terminal Amino ◽  
Membrane Isolation ◽  
Solubilized Form ◽  
Triton X ◽  
Hydrolysis Of

Renal dipeptidase (EC 3.4.13.11) has been solubilized from pig kidney microvillar membranes with n-octyl-beta-D-glucopyranoside and then purified by affinity chromatography on cilastatin-Sepharose. The enzyme exists as a disulphide-linked dimer of two identical subunits of Mr 45,000 each. The purified dipeptidase partitioned into the detergent-rich phase upon phase separation in Triton X-114 and reconstituted into liposomes consistent with the presence of the glycosyl-phosphatidylinositol membrane anchor. The N-terminal amino acid sequence of the amphipathic, detergent-solubilized, form of renal dipeptidase was identical with that of the hydrophilic, phospholipase-solubilized, form, locating the membrane anchor at the C-terminus of the protein. The glycosyl-phosphatidylinositol anchor of both purified and microvillar membrane renal dipeptidase was a substrate for an activity in pig plasma which displayed properties similar to those of a previously described phospholipase D. The cross-reacting determinant of the glycosyl-phosphatidylinositol anchor was generated by incubation of purified renal dipeptidase with bacterial phosphatidylinositol-specific phospholipase c, whereas the anchor-degrading activity in plasma failed to generate this determinant.

Hydrolyse von Per(fluorchlor)methylsulfenylchloriden: Isolierung und Charakterisierung stabiler Zwischenstufen / Hydrolysis of Per(fluorochloro)methylsulfenylchlorides: Isolation and Characterization of Stable Intermediates

1985 ◽  
Vol 40 (1) ◽  
pp. 32-38
Author(s):  
Alois Haas ◽  
Wolfgang Wanzke ◽  
Nathan Welcman
Keyword(s):  
Preparative Scale ◽  
Isolation And Characterization ◽  
Hydrolysis Of

Hydrolysis of CF3-nClnSCl with water yields the thiosulfinates CF3-nClnSS(O)CF3-nCln and thiosulfonates CF3-nClnSSO2CF3-nCln as stable intermediates. They were synthesized on a preparative scale by special reactions and characterized. A new mechanism, based upon additional reactions of the isolated products, is discussed and extended to the reaction of chlorine with water

CARBOXYLATION OF CROTONYL-CoA BY MAMMALIAN ENZYME SYSTEMS

1966 ◽  
Vol 44 (6) ◽  
pp. 861-878 ◽  
Author(s):  
E. Reno Tustanoff ◽  
Joseph R. Stern
Keyword(s):  
Carbon Dioxide ◽  
Enzyme System ◽  
Test System ◽  
Diabetic Rats ◽  
Isolation And Characterization ◽  
Unsaturated Acyl ◽  
Liver Preparation ◽  
Mammalian Enzyme ◽  
Hydrolysis Of

In a crude dialyzed ammonium sulfate fraction (35–65% saturation) of rat liver, carbon dioxide fixation into crotonyl-CoA took place when the test system was supplemented with ATP, Mn++, glutathione, Tris–HCl buffer (pH 7.0), and KH14CO3. The products of this reaction were identified after hydrolysis as glutaconic, β-hydroxyglutaric, maionic, and 2-ethylmalonic acids. The isolation and characterization of 5-14C-glutaconyl-CoA indicated a γ-carboxylation reaction. In the presence of endogenous enoyl-CoA hydratase, crotonyl-CoA was carboxylated more readily than β-hydroxybutyryl-CoA, suggesting that the unsaturated acyl compound was the natural substrate for the enzyme system. Carboxylation of crotonyl-CoA was greatly enhanced when liver extracts were prepared from either fasted or alloxan-diabetic rats. Fixation of carbon dioxide into crotonyl-CoA was also demonstrated with an amorphous preparation of propionyl-CoA carboxylase from pig heart. The products of this reaction were identified as radioactive malonic acid and unlabeled acetaldehyde, compounds which resulted from the alkaline hydrolysis of 2-ethylidenemalonyl-CoA, formed by the α-carboxylation of crotonyl-CoA. Evidence is presented that both α- and γ-carboxylation are catalyzed by the crude liver preparation.

scholarly journals Isolation and characterization of an activator protein for the hydrolysis of ganglioside GM2 from the roe of striped mullet (Mugil cephalus)

1989 ◽  
Vol 260 (3) ◽  
pp. 777-783 ◽  
Author(s):  
R DeGasperi ◽  
Y T Li ◽  
S C Li
Keyword(s):  
Mugil Cephalus ◽  
Striped Mullet ◽  
Activator Protein ◽  
Isolation And Characterization ◽  
Mammalian Tissues ◽  
Hexosaminidase A ◽  
Ammonium Sulphate Fractionation ◽  
Gm2 Activator ◽  
Hydrolysis Of

After the revelation of the presence of ganglioside GM2 as the major ganglioside in the roe of striped mullet, Mugil cephalus [Li, Hirabayashi, DeGasperi, Yu, Ariga, Koerner & Li (1984) J. Biol. Chem. 259, 8980-8985], we have continued to investigate the catabolism of GM2 in this tissue. We have found that mullet roe contains a specific activator protein which stimulates the hydrolysis of GM2 carried out by the beta-hexosaminidase isolated from the same tissue. This activator has been purified by using conventional procedures including ammonium sulphate fractionation and chromatography on Sepharose 6B, DEAE-Sephadex A-50, octyl-Sepharose and Matrex Gel Blue A columns. This activator protein is also able to stimulate the hydrolysis of GM2 carried out by human beta-hexosaminidase A. Unlike human GM2-activator, the roe activator protein does not stimulate the hydrolysis of GgOse3Cer or GbOse4Cer. The molecular mass (18 kDa) of the roe activator protein was found to be similar to that of human GM2-activator; however, the pI (pH 4.1) was found to be lower than that of human GM2-activator. This is the first report on the presence of a GM2-activator protein in a source other than mammalian tissues.

Isolation and characterization of polydentate ligands derived from the reaction of pentaerythrityltetrabromide and ethylenediamine

1989 ◽  
Vol 67 (10) ◽  
pp. 1657-1665 ◽  
Author(s):  
A. McAuley ◽  
K. Beveridge ◽  
S. Subramanian ◽  
T. W. Whitcombe
Keyword(s):  
Diethyl Malonate ◽  
Ring Closure ◽  
Polydentate Ligands ◽  
Isolation And Characterization ◽  
Free Amine ◽  
Square Planar ◽  
Bonding Interaction ◽  
Hydrolysis Of ◽  
Amine Hydrochlorides

Reaction of pentaerythrityltetrabromide with ethylenediamine yields three product amines. These have been isolated by separation of the corresponding Ni2+ complexes. The free amine hydrochlorides have been obtained by acid hydrolysis of the Ni2+ species and have been characterized by nuclear magnetic resonance and mass spectroscopy. The crystal structures have been determined for the hexahydrochloride salt of polyamine ligand L1, [H6(L1)]Cl6•4H2O (L1 = C11H28N6, 6,6-bis(4-amino-2-azabutyl)-1,4-diazacycloheptane)(C2/c, a = 15.975) Å, b = 10.723 (1) Å, c = 14.686(1) Å, β = 99.40(1)°, Z = 4), and for the octahydrochloride salt of L2, [H2(L2)Cl8•2H2O (L2 = 5,5-bis(4-amino-2-azabutyl)-1,9-diamino-3,7-diazanonane) (Pccn, a = 12.834(2) Å, b = 16.691(1) Å, c = 14.167(1) Å, Z = 4). Both crystals exhibit strong N—H … Cl,O,N bonding, although in the latter compound the waters of crystallization do not participate in the apparent hydrogen bonding interaction. Both these species are of interest since they represent the precursors to square planar Ni2+ complexes that incorporate the MN4 chromophore. Ring closure of both the free amines L1 and L2 by reaction with diethyl malonate leads to cyclized products that are related to the cyclam ([14-aneN4) tetraaza macrocylic ligands. Keywords: pentaerythrityl, amine, spiro ligand hydrochlorides.

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