scholarly journals Esterase Activity of Serum Albumin Studied by 1H NMR Spectroscopy and Molecular Modelling

2021 ◽  
Vol 22 (19) ◽  
pp. 10593
Author(s):  
Daria A. Belinskaia ◽  
Polina A. Voronina ◽  
Mikhail A. Vovk ◽  
Vladimir I. Shmurak ◽  
Anastasia A. Batalova ◽  
...  
Keyword(s):  
Serum Albumin ◽  
1H Nmr ◽  
Molecular Modelling ◽  
Esterase Activity ◽  
Proton Nuclear Magnetic Resonance ◽  
Spontaneous Hydrolysis ◽  
Mechanism Of Interaction ◽  
A Site ◽  
Hydrolysis Of ◽  
Albumin Molecule

Serum albumin possesses esterase and pseudo-esterase activities towards a number of endogenous and exogenous substrates, but the mechanism of interaction of various esters and other compounds with albumin is still unclear. In the present study, proton nuclear magnetic resonance (1H NMR) has been applied to the study of true esterase activity of albumin, using the example of bovine serum albumin (BSA) and p-nitrophenyl acetate (NPA). The site of BSA esterase activity was then determined using molecular modelling methods. According to the data obtained, the accumulation of acetate in the presence of BSA in the reaction mixture is much more intense as compared with the spontaneous hydrolysis of NPA, which indicates true esterase activity of albumin towards NPA. Similar results were obtained for p-nitophenyl propionate (NPP) as substrate. The rate of acetate and propionate release confirms the assumption that there is a site of true esterase activity in the albumin molecule, which is different from the site of the pseudo-esterase activity Sudlow II. The results of molecular modelling of BSA and NPA interaction make it possible to postulate that Sudlow site I is the site of true esterase activity of albumin.

Synthesis of conjugates of 1-(carboxymethyl)cytosine and 1-(5-O-carboxymethyl-β-D-arabinofuranosyl)cytosine with proteins

1979 ◽  
Vol 44 (10) ◽  
pp. 3023-3032 ◽  
Author(s):  
Helmut Pischel ◽  
Antonín Holý ◽  
Günther Wagner
Keyword(s):  
Human Serum Albumin ◽  
Acetic Anhydride ◽  
Serum Albumin ◽  
Human Serum ◽  
Activated Esters ◽  
Hydrolysis Of

1-(Carboxymethyl)cytosine (Ia), 1-(5-O-carboxymethyl-β-D-arabinofuranosyl)cytosine (IIa) and 5'-O-carboxylmethylcytidine (IIIa) were transformed by treatment with acetic anhydride and 4-dimethylaminopyridine to the peracetyl derivatives Ib-IIIb. These products reacted with p-nitrophenol in the presence of N, N'-dicyclohexylcarbodiimide to give the activated esters Ic-IIIc which on reaction with ammonia, dimethylamine or 2-aminoethanol afforded the corresponding carboxamides Id-IIId, IIe,f. Reactions of Ic and IIc with human serum albumin and bovine γ-globulin at pH 9.2, followed by hydrolysis of the N- or O-acetyl groups at pH 9.5, gave 50% up to 64% yields of the respective conjugates Ig, IIg and Ih, IIh.

ChemInform Abstract: HPLC and 1H NMR Studies of Alkaline Hydrolysis of Some 7-(Oxyiminoacyl) cephalosporins.

ChemInform ◽  
2010 ◽  
Vol 25 (11) ◽  
pp. no-no
Author(s):  
B. VILANOVA ◽  
F. MUNOZ ◽  
J. DONOSO ◽  
F. GARCIA BLANCO
Keyword(s):  
1H Nmr ◽  
Alkaline Hydrolysis ◽  
Nmr Studies ◽  
Hydrolysis Of

scholarly journals Neuroendocrine Neoplasms: Identification of Novel Metabolic Circuits of Potential Diagnostic Utility

Cancers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 374
Author(s):  
Beatriz Jiménez ◽  
Mei Ran Abellona U ◽  
Panagiotis Drymousis ◽  
Michael Kyriakides ◽  
Ashley K. Clift ◽  
...  
Keyword(s):  
1H Nmr ◽  
Cancer Metabolism ◽  
Proton Nuclear Magnetic Resonance ◽  
Neuroendocrine Neoplasms ◽  
Resonance Spectroscopy ◽  
Diagnostic Utility ◽  
Signalling Molecules ◽  
Prognostic Accuracy ◽  
Diagnostic Potential ◽  
Healthy Control

The incidence of neuroendocrine neoplasms (NEN) is increasing, but established biomarkers have poor diagnostic and prognostic accuracy. Here, we aim to define the systemic metabolic consequences of NEN and to establish the diagnostic utility of proton nuclear magnetic resonance spectroscopy (1H-NMR) for NEN in a prospective cohort of patients through a single-centre, prospective controlled observational study. Urine samples of 34 treatment-naïve NEN patients (median age: 59.3 years, range: 36–85): 18 had pancreatic (Pan) NEN, of which seven were functioning; 16 had small bowel (SB) NEN; 20 age- and sex-matched healthy control individuals were analysed using a 600 MHz Bruker 1H-NMR spectrometer. Orthogonal partial-least-squares-discriminant analysis models were able to discriminate both PanNEN and SBNEN patients from healthy control (Healthy vs. PanNEN: AUC = 0.90, Healthy vs. SBNEN: AUC = 0.90). Secondary metabolites of tryptophan, such as trigonelline and a niacin-related metabolite were also identified to be universally decreased in NEN patients, while upstream metabolites, such as kynurenine, were elevated in SBNEN. Hippurate, a gut-derived metabolite, was reduced in all patients, whereas other gut microbial co-metabolites, trimethylamine-N-oxide, 4-hydroxyphenylacetate and phenylacetylglutamine, were elevated in those with SBNEN. These findings suggest the existence of a new systems-based neuroendocrine circuit, regulated in part by cancer metabolism, neuroendocrine signalling molecules and gut microbial co-metabolism. Metabonomic profiling of NEN has diagnostic potential and could be used for discovering biomarkers for these tumours. These preliminary data require confirmation in a larger cohort.

scholarly journals Vapor Phase Modification for Selective Enrichment of Grafted Styrene/Acrylonitrile onto Carbon Nanotubes Via ATRP

Processes ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 459
Author(s):  
Maryam Azadbakht ◽  
Elnaz Esmizadeh ◽  
Ali Vahidifar ◽  
Tizazu H. Mekonnen ◽  
Mehdi Salami-Kalajahi
Keyword(s):  
Carbon Nanotubes ◽  
1H Nmr ◽  
Vapor Phase ◽  
Proton Nuclear Magnetic Resonance ◽  
Acid Vapor ◽  
Selective Enrichment ◽  
Pristine Mwcnts ◽  
Morphological Studies ◽  
Phase Oxidation ◽  
Multi Walled Carbon Nanotubes

Nitric acid vapor phase oxidation of multi-walled carbon nanotubes (MWCNTs) was proposed as a promising technique to fabricate poly styrene-co-acrylonitrile (SAN)-grafted-CNTs via atom transfer radical polymerization (ATRP). The in-situ ATRP grafting approach was successfully employed to graft polystyrene (PS), SAN and polyacrylonitrile (PAN), onto the convex surfaces of pristine MWCNTs (PCNT) and acid-functionalized MWCNTs (FCNT). Fourier transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance (1H-NMR), and thermogravimetric analysis (TGA) confirmed the effectiveness of the modification via the ATRP grafting approach. The molar composition of acrylonitrile in the synthesized copolymer on the surface of CNTs for an FCNTs was calculated to be about 80% and 67.5% by 1H-NMR and TGA respectively, whereas the value is lower for PCNTs. Morphological studies showed that SAN-grafted FCNTs exhibit rougher surface morphology compared to the SAN-grafted PCNTs. Moreover, the higher diameter of the FCNTs indicated the higher polymer content, which was coated onto CNTs functionalized by vapor-phase oxidation. Therefore, the vapor phase oxidation strategy employed in this study could be utilized as a general method to prepare CNTs which can serve as an ATRP macroinitiator for the fabrication of various polymer grafted CNTs.

Recreational drugs 25I-NBOH and 25I-NBOMe bind to both Sudlow's sites I and II of Human Serum Albumin (HSA): Biophysical and molecular modeling studies

2021 ◽  
Author(s):  
Wellington Alves de Barros ◽  
Marina de Magalhães Silva ◽  
Maria Dayanne de Araújo Dantas ◽  
Josue Santos ◽  
Isis Figueiredo ◽  
...  
Keyword(s):  
Molecular Modeling ◽  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Molecular Modelling ◽  
Recreational Drugs ◽  
Modeling Studies ◽  
Molecular Modelling Studies ◽  
Modelling Studies ◽  
Molecular Modeling Studies

Experimental, biophysical, and molecular modelling studies between 25I-NBOH and 25I-NBOMe with human serum albumin (HSA) have indicated that these recreational drugs simultaneously bind to site I and II of the...

Variation in Quantity of Methanol Recovered from Raisins

1963 ◽  
Vol 46 (2) ◽  
pp. 341-343
Author(s):  
M Alice Brown ◽  
James R Woodward ◽  
Floyd DeEds
Keyword(s):  
Methyl Ester ◽  
Esterase Activity ◽  
Enzymic Hydrolysis ◽  
Methanol Content ◽  
Naturally Occurring ◽  
Pectin Esterase ◽  
Hydrolysis Of

Abstract The amount of naturally occurring methanol in fruit must be known so that the quantity left as fumigation residue can be determined. In a study of methanol content of raisins, which had given inconsistent results, the raisins were subjected to different conditions of treatment immediately prior to methanol determination. Conditions that favored pectin esterase activity gave higher values for methanol content than conditions known to inactivate enzymes. Evidence was also obtained that both chemical and enzymic hydrolysis of methyl ester groups of pectic materials occur during analysis.

Polyhydroxyalkanoate quantification in organic wastes and pure cultures using a single-step extraction and 1H NMR analysis

2012 ◽  
Vol 66 (5) ◽  
pp. 1000-1006 ◽  
Author(s):  
Elisabeth Linton ◽  
Asif Rahman ◽  
Sridhar Viamajala ◽  
Ronald C. Sims ◽  
Charles D. Miller
Keyword(s):  
1H Nmr ◽  
Azotobacter Vinelandii ◽  
Nile Blue ◽  
Agricultural Waste ◽  
Accurate Method ◽  
Single Step ◽  
Proton Nuclear Magnetic Resonance ◽  
Copolymer Composition ◽  
Nmr Analysis ◽  
Nmr Method

In this study, a proton nuclear magnetic resonance (1H NMR) method was developed to quantitatively analyze polyhydroxyalkanoate (PHA) content in Cupriavidus necator H16, Azotobacter vinelandii AvOP, and mixed microbial cultures from the effluent of an agricultural waste treatment anaerobic digester. In contrast to previous methods, a single-step PHA extractive method using deuterated chloroform was established, thereby facilitating direct 1H NMR analysis. The accuracy of the method was verified through comparison with well-established gas chromatography (GC) methanolysis techniques. Nile blue fluorescence staining was also carried out to serve as an independent and qualitative indicator of intracellular PHA content. The results indicate that the 1H NMR method is appropriate for rapid and non-destructive quantification of overall PHA content and determination of PHA copolymer composition in a variety of cultures. Notably, this technique was effective in measuring PHA content in full-strength waste samples where high concentrations of background impurities and organic compounds are present. The straightforward procedures minimize error-introducing steps, require less time and materials, and result in an accurate method suitable for routine analyses.

Sign in / Sign up

Export Citation Format

Share Document