scholarly journals Insight into the esterase like activity demonstrated by an imidazole appended self-assembling hydrogelator

2015 ◽  
Vol 51 (67) ◽  
pp. 13213-13216 ◽  
Author(s):  
Nishant Singh ◽  
Maria P. Conte ◽  
R. V. Ulijn ◽  
Juan F. Miravet ◽  
Beatriu Escuder
Keyword(s):  
Methyl Ester ◽  
Self Assembling ◽  
Phenylalanine Methyl Ester ◽  
First Time ◽  
Hydrolysis Of ◽  
Insight Into

Hydrolysis of unactivated phenylalanine methyl ester by a simple imidazole appended hydrogelator is reported for the first time.

scholarly journals Comparative studies of the specificities of α-chymotrypsin and subtilisin BPN′. Studies with flexible substrates

1972 ◽  
Vol 126 (3) ◽  
pp. 645-657 ◽  
Author(s):  
T. N. Pattabiraman ◽  
W. B. Lawson
Keyword(s):  
Methyl Ester ◽  
Binding Site ◽  
Comparative Studies ◽  
Detrimental Effect ◽  
Flexible Substrates ◽  
Enhancing Effect ◽  
Wide Range ◽  
Phenylalanine Methyl Ester ◽  
Hydrolysis Of ◽  
Tryptophan Methyl Ester

A series of arylalkanoate esters and α-acetamidoarylalkanoate esters were tested as substrates for α-chymotrypsin and subtilisin BPN′. Chymotrypsin hydrolysed N-acetyl-l-phenylalanine methyl ester and methyl 4-phenylbutyrate faster than their respective higher and lower homologues, whereas methyl 2-acetamido-6-phenylhexanoate and methyl 6-phenylhexanoate were better substrates for subtilisin than their lower homologues. N-Acetyl-l-tryptophan methyl ester and its analogue, N-acetyl-3-(1-naphthyl)-alanine methyl ester, were hydrolysed 23 times faster by chymotrypsin than by subtilisin. These results indicate that the binding site of α-chymotrypsin is roughly 1.1nm (11Å) long and curved, whereas that of subtilisin is a longer system and less curved. The stereo-specificity during the hydrolysis of typical substrates by both enzymes was found to vary over a wide range. The enhancing effect of the α-acetamido group in the l-series of substrates and the detrimental effect in the d-series of substrates also varies considerably.

THE HYDROLYSIS OF PHENYLALANINE METHYL ESTER BY BOVINE THROMBIN

1966 ◽  
Vol 44 (7) ◽  
pp. 1051-1059 ◽  
Author(s):  
Edmond R. Cole ◽  
J. L. Koppel ◽  
John H. Olwin
Keyword(s):  
Methyl Ester ◽  
Sodium Citrate ◽  
Deae Cellulose ◽  
Amino Acid Esters ◽  
Bovine Thrombin ◽  
Wide Range ◽  
Autoprothrombin C ◽  
Phenylalanine Methyl Ester ◽  
Hydrolysis Of ◽  
Acid Esters

Thrombin, usually regarded as a trypsin-like enzyme capable of hydrolyzing only esters of the amino acids arginine and lysine, was found to hydrolyze certain other amino acid esters which are considered specific chymotrypsin substrates. L-Phenylalanine methyl ester inhibited the activation of purified bovine prothrombin by autoprothrombin C, Ac-globulin, phospholipid, and calcium. It was subsequently shown that thrombin is capable of hydrolyzing L-phenylalanine methyl ester or L-tyrosine ethyl ester. This activity developed simultaneously with fibrogen clotting activity during activation of purified bovine prothrombin in 25% sodium citrate solutions. Moreover, the activity was closely associated with clotting activity on subsequent chromatography on DEAE-cellulose and Amberlite IRC-50 resin columns. All preparations of bovine thrombin, representing a wide range of purity, which have been examined, exhibited this hydrolyzing activity toward L-phenylalanine methyl ester. Further evidence linking this esterase activity with fibrinogen clotting activity was obtained when both activities were inhibited by 2-nitro-4-carboxyphenyl-N,N-diphenylcarbamate, an inhibitor of chymotrypsin.

Aleksey Peshkov as an editor of Samarskaya Gazeta

2020 ◽  
pp. 128-138
Author(s):  
A. S. Bik-Bulatov
Keyword(s):  
Local History ◽  
Organizational Skills ◽  
First Time ◽  
New Evidence ◽  
Insight Into ◽  
Shed Light

The article uses little known letters of M. Gorky, many of which were published for the first time in 1997, as well as findings of Samara-based experts in local history to shed light on the writer’s work as editor-in-chief of the Samarskaya Gazeta newspaper in 1895. The researcher introduces hitherto unstudied reminiscences of the journalist D. Linyov (Dalin) about this period, which reference a letter by Gorky, now lost. The paper details a newly discovered episode of Gorky’s professional biography as a journalist: it concerns his campaign against a Samara ‘she-wolf,’ the madam of a local brothel A. Neucheva. Linyov’s reminiscences turn out to be an important and interesting source, offering an insight into the daily grind of the young editor Gorky, providing new evidence of his excellent organizational skills, and describing his moral and social stance. The author presents his work in the context of a recently initiated broader discussion about the need to map out all Russian periodicals for the period until 1917, as well as all research devoted to individual publications.

scholarly journals Comparative Study of Chemical Compositions and Antioxidant Capacities of Oils Obtained from 15 Macadamia (Macadamia integrifolia) Cultivars in China

Foods ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1031
Author(s):  
Xixiang Shuai ◽  
Taotao Dai ◽  
Mingshun Chen ◽  
Ruihong Liang ◽  
Liqing Du ◽  
...  
Keyword(s):  
Palmitoleic Acid ◽  
Linear Regression Analysis ◽  
Monounsaturated Fatty Acids ◽  
Multiple Linear Regression Analysis ◽  
Chemical Compositions ◽  
Macadamia Integrifolia ◽  
Antioxidant Capacities ◽  
Squalene Content ◽  
First Time ◽  
Insight Into

The planting area of macadamia in China accounted for more than one third of the world’s planted area. The lipid compositions, minor components, and antioxidant capacities of fifteen varieties of macadamia oil (MO) in China were comparatively investigated. All varieties of MO were rich in monounsaturated fatty acids, mainly including oleic acid (61.74–66.47%) and palmitoleic acid (13.22–17.63%). The main triacylglycerols of MO were first time reported, including 19.2–26.1% of triolein, 16.4–18.2% of 1-palmitoyl-2,3-dioleoyl-glycerol, and 11.9–13.7% of 1-palmitoleoyl-2-oleoyl-3-stearoyl-glycerol, etc. The polyphenol, α-tocotrienol and squalene content varied among the cultivars, while Fuji (791) contained the highest polyphenols and squalene content. Multiple linear regression analysis indicated the polyphenols and squalene content positively correlated with the antioxidant capacity. This study can provide a crucial directive for the breeding of macadamia and offer an insight into industrial application of MO in China.

scholarly journals ASKAP observations of multiple rapid scintillators reveal a degrees-long plasma filament

2021 ◽  
Vol 502 (3) ◽  
pp. 3294-3311
Author(s):  
Yuanming Wang ◽  
Artem Tuntsov ◽  
Tara Murphy ◽  
Emil Lenc ◽  
Mark Walker ◽  
...  
Keyword(s):  
Physical Properties ◽  
Angular Width ◽  
Scattering Medium ◽  
Central Frequency ◽  
Linear Arrangement ◽  
Plasma Filament ◽  
Kinematic Models ◽  
Tidal Stream ◽  
First Time ◽  
Insight Into

ABSTRACT We present the results from an Australian Square Kilometre Array Pathfinder search for radio variables on timescales of hours. We conducted an untargeted search over a 30 deg2 field, with multiple 10-h observations separated by days to months, at a central frequency of 945 MHz. We discovered six rapid scintillators from 15-min model-subtracted images with sensitivity of $\sim\! 200\, \mu$Jy/beam; two of them are extreme intra-hour variables with modulation indices up to $\sim 40{{\ \rm per\ cent}}$ and timescales as short as tens of minutes. Five of the variables are in a linear arrangement on the sky with angular width ∼1 arcmin and length ∼2 degrees, revealing the existence of a huge plasma filament in front of them. We derived kinematic models of this plasma from the annual modulation of the scintillation rate of our sources, and we estimated its likely physical properties: a distance of ∼4 pc and length of ∼0.1 pc. The characteristics we observe for the scattering screen are incompatible with published suggestions for the origin of intra-hour variability leading us to propose a new picture in which the underlying phenomenon is a cold tidal stream. This is the first time that multiple scintillators have been detected behind the same plasma screen, giving direct insight into the geometry of the scattering medium responsible for enhanced scintillation.

scholarly journals Rapid systemic surge of IL-33 after severe human trauma: a prospective observational study

2021 ◽  
Vol 27 (1) ◽  
Author(s):  
Olav Sundnes ◽  
William Ottestad ◽  
Camilla Schjalm ◽  
Peter Lundbäck ◽  
Lars la Cour Poulsen ◽  
...  
Keyword(s):  
High Resolution ◽  
Prospective Observational Study ◽  
Tissue Injury ◽  
Trauma Patients ◽  
Decoy Receptor ◽  
Interleukin 33 ◽  
Injured Patients ◽  
First Time ◽  
Kinetics Of ◽  
Insight Into

Abstract Background Alarmins are considered proximal mediators of the immune response after tissue injury. Understanding their biology could pave the way for development of new therapeutic targets and biomarkers in human disease, including multiple trauma. In this study we explored high-resolution concentration kinetics of the alarmin interleukin-33 (IL-33) early after human trauma. Methods Plasma samples were serially collected from 136 trauma patients immediately after hospital admission, 2, 4, 6, and 8 h thereafter, and every morning in the ICU. Levels of IL-33 and its decoy receptor sST2 were measured by immunoassays. Results We observed a rapid and transient surge of IL-33 in a subset of critically injured patients. These patients had more widespread tissue injuries and a greater degree of early coagulopathy. IL-33 half-life (t1/2) was 1.4 h (95% CI 1.2–1.6). sST2 displayed a distinctly different pattern with low initial levels but massive increase at later time points. Conclusions We describe for the first time early high-resolution IL-33 concentration kinetics in individual patients after trauma and correlate systemic IL-33 release to clinical data. These findings provide insight into a potentially important axis of danger signaling in humans.

scholarly journals Structural analysis of cross α-helical nanotubes provides insight into the designability of filamentous peptide nanomaterials

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Fengbin Wang ◽  
Ordy Gnewou ◽  
Charles Modlin ◽  
Leticia C. Beltran ◽  
Chunfu Xu ◽  
...  
Keyword(s):  
Structural Analysis ◽  
Synthetic Peptide ◽  
Quaternary Structure ◽  
De Novo ◽  
Rational Approach ◽  
Lateral Interactions ◽  
Protein Assemblies ◽  
Self Assembling ◽  
Arginine Residues ◽  
Insight Into

AbstractThe exquisite structure-function correlations observed in filamentous protein assemblies provide a paradigm for the design of synthetic peptide-based nanomaterials. However, the plasticity of quaternary structure in sequence-space and the lability of helical symmetry present significant challenges to the de novo design and structural analysis of such filaments. Here, we describe a rational approach to design self-assembling peptide nanotubes based on controlling lateral interactions between protofilaments having an unusual cross-α supramolecular architecture. Near-atomic resolution cryo-EM structural analysis of seven designed nanotubes provides insight into the designability of interfaces within these synthetic peptide assemblies and identifies a non-native structural interaction based on a pair of arginine residues. This arginine clasp motif can robustly mediate cohesive interactions between protofilaments within the cross-α nanotubes. The structure of the resultant assemblies can be controlled through the sequence and length of the peptide subunits, which generates synthetic peptide filaments of similar dimensions to flagella and pili.

scholarly journals Cold-Active β-Galactosidases: Insight into Cold Adaption Mechanisms and Biotechnological Exploitation

Marine Drugs ◽  
2021 ◽  
Vol 19 (1) ◽  
pp. 43
Author(s):  
Marco Mangiagalli ◽  
Marina Lotti
Keyword(s):  
Low Temperature ◽  
Molecular Mechanisms ◽  
Building Blocks ◽  
Cold Active ◽  
Cold Adaption ◽  
Glycosyl Donor ◽  
Pharmaceutical Industries ◽  
Biotechnological Processes ◽  
Hydrolysis Of ◽  
Insight Into

β-galactosidases (EC 3.2.1.23) catalyze the hydrolysis of β-galactosidic bonds in oligosaccharides and, under certain conditions, transfer a sugar moiety from a glycosyl donor to an acceptor. Cold-active β-galactosidases are identified in microorganisms endemic to permanently low-temperature environments. While mesophilic β-galactosidases are broadly studied and employed for biotechnological purposes, the cold-active enzymes are still scarcely explored, although they may prove very useful in biotechnological processes at low temperature. This review covers several issues related to cold-active β-galactosidases, including their classification, structure and molecular mechanisms of cold adaptation. Moreover, their applications are discussed, focusing on the production of lactose-free dairy products as well as on the valorization of cheese whey and the synthesis of glycosyl building blocks for the food, cosmetic and pharmaceutical industries.

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