scholarly journals Comparative studies of four monoclonal antibodies to phenylalanine hydroxylase exhibiting different properties with respect to substrate-dependence, species-specificity and a range of effects on enzyme activity

1981 ◽  
Vol 199 (3) ◽  
pp. 527-535 ◽  
Author(s):  
K H Choo ◽  
I G Jennings ◽  
R G H Cotton
Keyword(s):  
Enzyme Activity ◽  
Monoclonal Antibodies ◽  
Comparative Studies ◽  
Phenylalanine Hydroxylase ◽  
The Other ◽  
Preliminary Characterization ◽  
Substrate Dependence ◽  
One Step ◽  
First Time

Four monoclonal antibodies to phenylalanine hydroxylase are described. Two are inhibitory (PH alpha 1-1 and PH alpha 2-1-1 antibodies), one is stimulatory (B5-1 antibody) and one has no effect on enzyme activity (PH alpha 3-0 antibody). Their properties are compared. Two antibodies (PH alpha 1-1 and B5-1 antibodies) bind primate and rodent phenylalanine hydroxylase, whereas the other two (PH alpha 2-1-1 and PH alpha 3-0 antibodies) bind only the primate enzyme. The binding of PH alpha 1-1 antibody to phenylalanine hydroxylase is dependent on substrate phenylalanine, whereas the binding of the others is not influenced by phenylalanine. Affinity adsorbents prepared from the four antibodies purified phenylalanine hydroxylase substantially (greater than 80% purity) in one step, except for a PH alpha 3-0 antibody--Sepharose column, which behaved anomalously. Two previous publications described the isolation and preliminary characterization of B5 and PH alpha 1-1 antibodies. PH alpha 2-1-1 and PH alpha 3-0 antibodies are reported for the first time.

scholarly journals Identification and Characterization of α-Glucosidase Inhibition Flavonol Glycosides from Jack Bean (Canavalia ensiformis (L.) DC

Molecules ◽  
2020 ◽  
Vol 25 (11) ◽  
pp. 2481
Author(s):  
Anita M. Sutedja ◽  
Emiko Yanase ◽  
Irmanida Batubara ◽  
Dedi Fardiaz ◽  
Hanifah N. Lioe
Keyword(s):  
2D Nmr ◽  
The Other ◽  
Inhibition Activity ◽  
Jack Bean ◽  
Canavalia Ensiformis ◽  
Kaempferol Glycosides ◽  
Uv Visible ◽  
First Time ◽  
Identification And Characterization

Although the intake of jack bean (Canavalia ensiformis (L.) DC.), an underutilized tropical legume, can potentially decrease the risk of several chronic diseases, not much effort has been directed at profiling the polyphenolics contained therein. Hence, this work aimed to identify and quantify the dominant jack bean polyphenolics, which are believed to have antioxidant and other bioactivities. Four major compounds were detected and identified as kaempferol glycosides with three or four glycoside units. Their structures were established based on UV-visible, 1D, 2D NMR, and HR-ESI-MS analyses. Specifically, kaempferol 3-O-α-l-rhamnopyranosyl (1→6)- β-d-glucopyranosyl (1→2)-β-d-galactopyranosyl-7-O-[3-O-o-anisoyl]-α-l-rhamnopyranoside was detected for the first time, while the other three compounds have already been described in plants other than jack bean. This new compound was found to have a higher α-glucosidase inhibition activity compared to acarbose.

scholarly journals Isolation and characterization of bleomycin-resistant clones of CHO cells

1979 ◽  
Vol 34 (3) ◽  
pp. 269-279 ◽  
Author(s):  
Sylvia Brabbs ◽  
J. R. Warr
Keyword(s):  
Enzyme Activity ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Tween 80 ◽  
The Other ◽  
Resistant Clone ◽  
Ovary Cells ◽  
Isolation And Characterization ◽  
Significant Difference

SUMMARYFive clones of Chinese hamster ovary cells with increased resistance to bleomycin have been isolated following ethylmethanesulphonate mutagenesis. Resistance was stable in three of the clones, but unstable in the other two. One of the stably resistant clones was cross resistant to unrelated drugs, and in contrast to the parental cells, its response to bleomycin was potentiated by tween 80. These two observations suggested a membrane alteration in the resistant clone. There was no significant difference in bleomycin-inactivating enzyme activity between the parental and resistant clones.

scholarly journals THE PRODUCTION OF MONOCLONAL ANTIBODIES TO TETRASACCHARIDE - SYNTHETIC ANALOGUE OF THE CAPSULAR POLYSACCHARIDE OF STREPTOCOCCUS PNEUMONIAE OF SEROTYPE 14 AND THEIR IMMUNOCHEMICAL CHARACTERIZATION

2018 ◽  
pp. 26-31
Author(s):  
I. V. Yakovleva ◽  
E. A. Kurbatova ◽  
E. A. Akhmatova ◽  
E. V. Sukhova ◽  
D. V. Yashunsky ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Streptococcus Pneumoniae ◽  
Capsular Polysaccharide ◽  
Solid Phase ◽  
Synthetic Analogue ◽  
Immunochemical Characterization ◽  
Carbohydrate Epitopes ◽  
First Time

Aim. Production of monoclonal antibodies (mAb) to synthetic tetrasaccharide - repeating unit of the capsular polysaccharide (CP) of Streptococcus pneumoniae serotype 14 and their immunochemical characterization. Materials and methods. In order to generate the hybridoma producing mAb, mice were immunized with synthetic tetrasaccharide conjugated with bovine serum albumin (BSA) with following hybridization of B lymphocytes with mouse myeloma cells. Antibodies were obtained in vitro andin vivo. Immunochemical characterization of mAb to tetrasaccharide was carried out using a variety of ELISA options. Results. For the first time obtained mouse hybridoma, producing IgM to tetrasacchride. The IgM titer of anti-tetrasacharide antibodies in supernatants of clones and in the ascitic fluid of mice in ELISA detected by biotinylated tetrasaccharide and synthetic CP adsorbed on the solid phase was higher compared to the use of bacterial CP as well cover antigen. In the reaction of inhibition of the ELISA, the mAb recognized the corresponding carbohydrate epitopes of the bacterial CP of S. pneumoniae serotype 14 dissolved in the liquid phase better than tetrasaccharide ligand and synthetic CP. Conclusion. To detect mAb to tetrasaccharide in ELISA preferably to use synthetic analogues of the CP as solid phase antigens. The obtained mAb to tetrasaccharide can be used to determine the representation of the protective tetrasaccharide epitope of CP in the development of pneumococcal vaccines.

Isolation and Characterization of a Chlorogenic Acid Esterase from Aspergillus niger

1980 ◽  
Vol 35 (3-4) ◽  
pp. 209-212 ◽  
Author(s):  
B. Schöbel ◽  
W. Pollmann
Keyword(s):  
Enzyme Activity ◽  
Chlorogenic Acid ◽  
Divalent Cations ◽  
Hydrolysis Product ◽  
The Other ◽  
Temperature Optimum ◽  
Pig Liver ◽  
Isolation And Characterization

Abstract The isolation and characterization of a specific chlorogenic acid esterase is described. The enzyme activity is measured by determination of the hydrolysis product caffeic acid. The enzyme had been concentrated by means of ultrafiltration and column-chromatography. The pH- and temperature optimum were 6.5 and 45 °C respectively. Divalent cations were not required for the enzyme activity. As other esterases, this enzyme is inhibited by di-isopropyl-phosphorofluoridate. The Km-value is 0.70 mᴍ chlorogenic acid, the molecular weight 240000. The described enzyme is specific for chlorogenic acid. On the other hand a typical unspecific esterase like the pig liver esterases does not split chloro­genic acid. The isoelectric focusing reveals several isoenzymes of chlorogenase within a pI-range of 4.0-4.5.

Preparation and preliminary characterization of new monoclonal antibodies versus estradiol receptor

1991 ◽  
Vol 27 ◽  
pp. S71
Author(s):  
C. Abbondanza ◽  
A. de Falco ◽  
V. Nigro ◽  
B. Moncharmont ◽  
N. Medici ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Preliminary Characterization ◽  
Estradiol Receptor

scholarly journals Functional analysis of the effect of monoclonal antibodies on monkey liver phenylalanine hydroxylase

1986 ◽  
Vol 235 (1) ◽  
pp. 133-138 ◽  
Author(s):  
I G Jennings ◽  
R G M Russell ◽  
W L F Armarego ◽  
R G H Cotton
Keyword(s):  
Functional Analysis ◽  
Enzyme Activity ◽  
Monoclonal Antibodies ◽  
Structural Changes ◽  
Phenylalanine Hydroxylase ◽  
Functional Characteristics ◽  
Monkey Liver

An analysis of the effect of eleven monoclonal antibodies on the functional characteristics of monkey liver phenylalanine hydroxylase is presented. These eleven antibodies have been found to react with eight distinct regions on the phenylalanine hydroxylase protein. PH1 antibody inhibits enzyme activity, is dependent on phenylalanine for its binding, and appears to be related to structural changes occurring during phenylalanine activation of the enzyme activity. PH2 and PH3 antibodies stimulate enzyme activity, their binding is inhibited by lysolecithin and this group apparently is recognizing structures involved in lysolecithin activation of the enzyme activity. PH5, PH10, PH12 and PH6 recognise sites on phenylalanine hydroxylase affected by lysolecithin activation.

Preparation and Preliminary Characterization of Rabbit Monoclonal Antibodies Against Human Midkine

Hybridoma ◽  
2011 ◽  
Vol 30 (1) ◽  
pp. 87-93 ◽  
Author(s):  
Xing Yao ◽  
Fu-Chu Qian ◽  
Li-Cheng Dai ◽  
Li-Shan Min
Keyword(s):  
Monoclonal Antibodies ◽  
Preliminary Characterization
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