Trapping RNase A on MCM41 pores: effects on structure stability, product inhibition and overall enzymatic activity

2014 ◽  
Vol 16 (19) ◽  
pp. 9031-9038 ◽  
Author(s):  
Irina Matlahov ◽  
Yasmin Geiger ◽  
Gil Goobes
Keyword(s):  
Enzymatic Activity ◽  
Product Inhibition ◽  
Rnase A ◽  
Structure Stability

Ribonuclease's activity bound to nano-sized pore openings of MCM41 is severely quenched, but inhibition by the product is reduced.

Thermal stability and enzymatic activity of RNase A in the presence of cationic gemini surfactants

2012 ◽  
Vol 50 (4) ◽  
pp. 1151-1157 ◽  
Author(s):  
Razieh Amiri ◽  
Abdol-Khalegh Bordbar ◽  
Douglas V. Laurents ◽  
Ahmad Reza Khosropour ◽  
Iraj Mohammadpoor-Baltork
Keyword(s):  
Thermal Stability ◽  
Enzymatic Activity ◽  
Gemini Surfactants ◽  
Rnase A ◽  
Cationic Gemini Surfactants

The Correlation of RNase A Enzymatic Activity with the Changes in the Distance between Nε2-His12 and Nδ1-His119 Upon Addition of Stabilizing and Destabilizing Salts

2006 ◽  
Vol 25 (2) ◽  
pp. 117-125 ◽  
Author(s):  
A. A. Moosavi-Movahedi ◽  
M. Gharanfoli ◽  
S. Jalili ◽  
F. Ahmad ◽  
J. Chamani ◽  
...  
Keyword(s):  
Enzymatic Activity ◽  
Rnase A

scholarly journals Switching the enzymatic activity of ribonuclease a based on enzyme/polymer complex formation

2014 ◽  
Vol 20 ◽  
pp. 33-39 ◽  
Author(s):  
Sumon Ganguli
Keyword(s):  
Heat Treatment ◽  
Spectral Analysis ◽  
Complex Formation ◽  
Acrylic Acid ◽  
Enzymatic Activity ◽  
Heat Resistance ◽  
Rnase A ◽  
Polymer Complex ◽  
Poly Ethylene Glycol ◽  
Poly Ethylene

Context: Enzymes are ideal for various applications in both medicine and biotechnology. Switching on/off the enzymatic activity of enzymes by polymeric modification would expand the applications of enzymes in a wide range of research fields. Objectives: On/off switching the enzymatic activity of RNase A and the confirmation of the enzyme/polymer complex formation which leads to improve the heat resistance of RNase A. Materials and Methods: ?-Methoxy-?-methacryloyl poly (ethylene glycol) (PEG-MA) macromonomer and PEAMA-g-PEG were synthesized. Bovine RNase A, cytidine 2?,3?-cyclic monophosphate sodium salt (cCMP), and 3-(N-morpholino)propanesulfonic acid (MOPS) were obtained from Sigma Chemical Co. (St. Louis, USA). PAAc (Mn = 5,000 g/mol) were purchased from Wako (Osaka, Japan). Sodium dihydrogen phosphate dihydrate (NaH2PO4.2H2O) was obtained from Nacalai Tesque Inc. (Kyoto, Japan). The enzymatic activity of RNase A was estimated as follows. The RNase A concentration was determined by measuring the absorbance at 280 nm with an appropritate blank, using an extinction coefficient of 7.10 mL mg-1 cm-1. A total of 1.5 mL of 0.1 mg/mL cCMP solution prepared in 0.1 M MOPS (pH 7.0) was mixed with 10 ?L of the RNase A solution in 50 mM sodium phosphate buffer (pH 7.0). The increase in light scattering intensity of the solution was monitored by measuring the absorbance at 284 nm for 60 s in a UV-vis spectrophotometer at room temperature. After heat treatment, the enzymatic activities were measured. Far-UV and near-UV CD spectra were monitored using a spectropolarimeter (model J-720W; Jasco, Tokyo, Japan). Results: We have found that poly (acrylic acid) (PAAc) suppressed the enzymatic activity of RNase A completely and the recovery of enzymatic activity were observed (94%) by the external addition of PEAMA-g-PEG to the RNase A/PAAc complex. Our present findings suggest that the complexation between PEAMA-g-PEG and RNase A has occurred which improve the heat resistance (64%) of RNase A. Heat treatment has been carried out at 98°C for 10 minutes where the native RNase A lost all of its enzymatic activity. CD spectral analysis also indicates that the conformation of the enzyme was not altered due to the complexation. Conclusion: Poly (N,N-diethylaminoethyl methacrylate)-graft-poly (ethylene glycol) (PEAMA-g-PEG) restored the enzymatic activity of RNase A completely which was inactivated upon the addition of poly(acrylic acid) (PAAc) to RNase A. Complexation of RNase A with PEAMA-g-PEG induced the improvement of heat resistance of RNase A . Circular dichroism (CD) spectral analysis clearly indicated that the complexation of enzyme with polymer has almost no influence on the conformation of enzyme. DOI: http://dx.doi.org/10.3329/jbs.v20i0.17650 J. bio-sci. 20: 33-39, 2012

scholarly journals N-glycosylation modulates enzymatic activity of Trypanosoma congolense trans-sialidase

2021 ◽  
Author(s):  
Jana Rosenau ◽  
Isabell Louise Grothaus ◽  
Yikun Yang ◽  
Lucio Colombi Ciacchi ◽  
Soerge Kelm ◽  
...  
Keyword(s):  
Enzymatic Activity ◽  
Conformational Changes ◽  
Trypanosoma Congolense ◽  
Structure Stability ◽  
Substrate Affinity ◽  
Substrate Complex ◽  
Enzyme Substrate ◽  
Function Relationship ◽  
Dynamics Simulations ◽  
Conserved Amino Acids

Trypanosomes cause the devastating disease trypanosomiasis, in which the action of trans-sialidase (TS) enzymes harbored on their surface is a key virulence factor. TS are highly N-glycosylated, but the biological functions of the glycans remain elusive. In this study, we investigated the influence of N-glycans on the enzymatic activity and structure stability of TconTS1, a recombinant TS from the African parasite Trypanosoma congolense. MALDI-TOF MS revealed that eight asparagine sites were glycosylated with high-mannose type N-glycans. Deglycosylation of TconTS1 led to a 5-fold decrease in substrate affinity but to the same conversion rate relative to the untreated enzyme. After deglycosylation, no changes in secondary structure elements were observed in circular dichroism experiments. Molecular dynamics simulations revealed interactions between the highly flexible N-glycans and some conserved amino acids belonging to the catalytic site. These interactions led to conformational changes, possibly enhancing substrate accessibility and promoting enzyme/substrate complex stability. The here-observed modulation of catalytic activity via the N-glycan shield may be a structure-function relationship intrinsic of several members of the TS family.

Substrate-leash amplification with ribonuclease S-peptide and S-protein.

1986 ◽  
Vol 32 (9) ◽  
pp. 1622-1630 ◽  
Author(s):  
M Ehrat ◽  
D J Cecchini ◽  
R W Giese
Keyword(s):  
Enzymatic Activity ◽  
Rnase A ◽  
S Protein ◽  
Protein Fragments ◽  
Polycytidylic Acid ◽  
Amplification System ◽  
Protein Gels ◽  
Acid Substrate

Abstract The S-peptide and S-protein fragments of ribonuclease S (RNase S, no EC no. assigned) have been immobilized onto separate Sepharose gels via a "leash" of polycytidylic acid substrate. Each of these gels releases its RNase fragment when treated with the complementary enzyme fragment or with RNase A (EC 3.1.27.5), and the released fragments recombine to give RNase S activity. Thus this system provides substrate-leash amplification (SLA), such that more enzymatic activity is eluted from the system than is applied. For example, 100 pg of RNase applied to the S-peptide gel is amplified by 1.9 X 10(4) to the equivalent of 1.9 micrograms of activity in 20 h, when followed by combination of the released S-peptide with excess S-protein. We also tested a three-stage amplification system, with a pair of S-peptide and S-protein gels at each stage. In this system the cumulative amplification of the initial 1-ng dose of RNase A is 4.9, 52, and 25-fold after each stage, respectively. Only 2 mg of each SLA gel is used per stage in these experiments, reflecting the magnitude of their production of RNase S activity.

Portein-gold labelling of ultrathin sections of wheat spot mosaic-affected wheat plants

1990 ◽  
Vol 48 (3) ◽  
pp. 680-681
Author(s):  
K. S. Zaychuk ◽  
M. H. Chen ◽  
C. Hiruki
Keyword(s):  
Osmium Tetroxide ◽  
Rnase A ◽  
Leaf Ultrastructure ◽  
Double Membrane ◽  
Young Root ◽  
Leaf Tissues ◽  
Membrane Bound ◽  
Ultrathin Sections ◽  
Gold Labelling ◽  
Electron Dense Core

Wheat spot mosaic (WSpM), which frequently occurs with wheat streak mosaic virus was first reported in 1956 from Alberta. Singly isolated, WSpM causes chlorotic spots, chlorosis, stunting, and sometimes death of the wheat plants. The vector responsible for transmission is the eriophyid mite, Eriophyes tulipae Kiefer. The examination of leaf ultrastructure by electron microscopy has revealed double membrane bound bodies (DMBB’s) 0.1-0.2 μm in diameter. Dispersed fibrils within these bodies suggested the presence of nucleic acid. However, neither ribosomes characteristic of bacteria, mycoplasma and the psittacosis group of organisms nor an electron dense core characteristic of many viruses was commonly evident.In an attempt to determine if the DMBB’s contain nucleic acids, RNase A, DNase I, and lactoferrin protein were conjugated with 10 nm colloidal gold as previously described. Young root and leaf tissues from WSpM-affected wheat plants were fixed in glutaraldehyde, postfixed in osmium tetroxide,and embedded in Spurr’s resin.

A Method for the Colorimetric Determination of β-Glucuronidase in Urine, Serum, Tissue; Assay of Enzymatic Activity in Health and Disease

1959 ◽  
Vol 36 (2) ◽  
pp. 193-201 ◽  
Author(s):  
Julius A. Goldbarg ◽  
Esteban P. Pineda ◽  
Benjamin M. Banks ◽  
Alexander M. Rutenburg
Keyword(s):  
Enzymatic Activity ◽  
Colorimetric Determination ◽  
Health And Disease ◽  
Urine Serum

Development and Psychometric Evaluation of a Revised Sense of Coherence Scale

2018 ◽  
Vol 34 (3) ◽  
pp. 206-215 ◽  
Author(s):  
Rahel Bachem ◽  
Andreas Maercker
Keyword(s):  
Posttraumatic Growth ◽  
Factor Structure ◽  
Sense Of Coherence ◽  
Psychological Health ◽  
Psychometric Evaluation ◽  
Health Indicators ◽  
Structure Stability ◽  
Confirmatory Factor Analyses ◽  
Reliability Factor ◽  
Two Samples

Abstract. The present study introduces a revised Sense of Coherence (SOC) scale, a new conceptualization and operationalization of the resilience indicator SOC. It outlines the scale development and aims for testing its reliability, factor structure, and validity. Literature on Antonovsky’s SOC (SOC-A) was critically reviewed to identify needs for improving the scale. The scale was investigated in two samples. Sample 1 consisted of 334 bereaved participants, Sample 2 of 157 healthy controls. The revised SOC Scale, SOC-A, and theoretically relevant questionnaires were applied. Explorative and confirmatory factor analyses established a three-factor structure in both samples. The revised SOC Scale showed significant but discriminative associations with related constructs, including self-efficacy, posttraumatic growth, and neuroticism. The revised measure was significantly associated with psychological health indicators, including persistent grief, depression, and anxiety, but not to the extent as the previous SOC-A. Stability over time was sufficient. The study provides psychometric support for the revised SOC conceptualization and scale. It has several advantages over the previous SOC-A scale (unique variance, distinct factor structure, stability). The scale could be used for clinical and health psychological testing or research into the growing field of studies on resilience over the life span.

Physiological and enzymatic activity of pepper seeds (Capsicum annuum) during priming

1991 ◽  
Vol 82 (3) ◽  
pp. 433-439 ◽  
Author(s):  
Patrick T. Smith ◽  
B. Greg Cobb
Keyword(s):  
Enzymatic Activity ◽  
Capsicum Annuum
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