scholarly journals Characteristics and Activity Changes of Proteolytic Enzymes in Apple Leaves during Autumnal Senescence

1982 ◽  
Vol 70 (5) ◽  
pp. 1367-1372 ◽  
Author(s):  
Seong-Mo Kang ◽  
Hiroyuki Matsui ◽  
John S. Titus
Keyword(s):  
Proteolytic Enzymes ◽  
Apple Leaves ◽  
Autumnal Senescence

The ubiquitin–proteasome system and skeletal muscle wasting

2005 ◽  
Vol 41 ◽  
pp. 173-186 ◽  
Author(s):  
Didier Attaix ◽  
Sophie Ventadour ◽  
Audrey Codran ◽  
Daniel Béchet ◽  
Daniel Taillandier ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Wasting ◽  
Proteolytic Enzymes ◽  
Cathepsin L ◽  
Ubiquitin Proteasome System ◽  
Complete Breakdown ◽  
Skeletal Muscle Proteins ◽  
Ubiquitin Proteasome ◽  
Tripeptidyl Peptidase Ii ◽  
F Box Protein

The ubiquitin–proteasome system (UPS) is believed to degrade the major contractile skeletal muscle proteins and plays a major role in muscle wasting. Different and multiple events in the ubiquitination, deubiquitination and proteolytic machineries are responsible for the activation of the system and subsequent muscle wasting. However, other proteolytic enzymes act upstream (possibly m-calpain, cathepsin L, and/or caspase 3) and downstream (tripeptidyl-peptidase II and aminopeptidases) of the UPS, for the complete breakdown of the myofibrillar proteins into free amino acids. Recent studies have identified a few critical proteins that seem necessary for muscle wasting {i.e. the MAFbx (muscle atrophy F-box protein, also called atrogin-1) and MuRF-1 [muscle-specific RING (really interesting new gene) finger 1] ubiquitin–protein ligases}. The characterization of their signalling pathways is leading to new pharmacological approaches that can be useful to block or partially prevent muscle wasting in human patients.

Recent data on the causative agent of pale green dwarf (Acholeplasma laidlawii var. granulum incertae sedis) in Ukraine: pathogenicityand virulence factors and host reactions

2015 ◽  
Vol 2 (1) ◽  
pp. 30-34
Author(s):  
K. Korobkova ◽  
V. Patyka
Keyword(s):  
Phenylalanine Ammonia Lyase ◽  
Proteolytic Enzymes ◽  
Physiological State ◽  
Plant Cells ◽  
Temporary Increase ◽  
Adhesive Properties ◽  
The Impact ◽  
Signaling Interactions ◽  
Pale Green

Contemporary state of the distribution of mycoplasma diseases of cultivated crops in Ukraine was analyzed. The changes of the physiological state of plant cells under the impact of mollicutes were investigated. It was demonstrated that there is temporary increase in the activity of peroxidase, catalase, polyphenoloxidase, phenylalanine-ammonia-lyase at the early stages of interaction. The adhesive properties are changed in the mollicutes under the impact of plant lectin; there is synthesis of new polypeptides. It was determined that the phytopathogenic acholeplasma is capable of producing a complex of proteolytic enzymes into the culture me- dium. It was concluded that when plant cells are infected with acholeplasma, a number of signaling interactions and metabolic transformations condition the recognition of pathogenesis and ensure the aggregate response of a plant to stress in the form of defense reactions. It was assumed that some specifi cities of the biology of phy- topathogenic acholeplasma determine their avoiding the immune mechanisms of plants and promote long-term persistence of mollicutes.

Estimating nitrogen contents of apple leaves based on hyperspectral parameter models at different phenophases

2016 ◽  
Vol 6 (2) ◽  
pp. 942-952
Author(s):  
Xicun ZHU ◽  
Zhuoyuan WANG ◽  
Lulu GAO ◽  
Gengxing ZHAO ◽  
Ling WANG
Keyword(s):  
Neural Network ◽  
Network Model ◽  
Neural Network Model ◽  
Bp Neural Network ◽  
Shoot Growth ◽  
Hyperspectral Data ◽  
Estimation Model ◽  
Apple Leaves ◽  
Bp Neural Network Model ◽  
Nitrogen Contents

The objective of the paper is to explore the best phenophase for estimating the nitrogen contents of apple leaves, to establish the best estimation model of the hyperspectral data at different phenophases. It is to improve the apple trees precise fertilization and production management. The experiments were done in 20 orchards in the field, measured hyperspectral data and nitrogen contents of apple leaves at three phenophases in two years, which were shoot growth phenophase, spring shoots pause growth phenophase, autumn shoots pause growth phenophase. The study analyzed the nitrogen contents of apple leaves with its original spectral and first derivative, screened sensitive wavelengths of each phenophase. The hyperspectral parameters were built with the sensitive wavelengths. Multiple stepwise regressions, partial least squares and BP neural network model were adopted in the study. The results showed that 551 nm, 716 nm, 530 nm, 703 nm; 543 nm, 705 nm, 699 nm, 756 nm and 545 nm, 702 nm, 695 nm, 746 nm were sensitive wavelengths of three phenophases. R551+R716, R551*R716, FDR530+FDR703, FDR530*FDR703; R543+R705, R543*R705, FDR699+FDR756, FDR699*FDR756and R545+R702, R545*R702, FDR695+FDR746, FDR695*FDR746 were the best hyperspectral parameters of each phenophase. Of all the estimation models, the estimated effect of shoot growth phenophase was better than other two phenophases, so shoot growth phenophase was the best phenophase to estimate the nitrogen contents of apple leaves based on hyperspectral models. In the three models, the 4-3-1 BP neural network model of shoot growth phenophase was the best estimation model. The R2 of estimated value and measured value was 0.6307, RE% was 23.37, RMSE was 0.6274.

Novel Approaches for Oral Delivery of Insulin and Current Status of Oral Insulin Products

2010 ◽  
Vol 3 (3) ◽  
pp. 1057-1064 ◽  
Author(s):  
Kinesh V P ◽  
Neelam D P ◽  
Punit B ◽  
Bhavesh S.B ◽  
Pragna K. S
Keyword(s):  
Diabetes Mellitus ◽  
Oral Delivery ◽  
Proteolytic Enzymes ◽  
Oral Route ◽  
The Body ◽  
Current Status ◽  
Intestinal Lumen ◽  
Insulin Administration ◽  
Novel Approaches ◽  
Dose Dependent

Diabetes mellitus is a serious pathologic condition that is responsible for major healthcare problems worldwide and costing billions of dollars annually. Insulin replacement therapy has been used in the clinical management of diabetes mellitus for more than 84 years. The present mode of insulin administration is by the subcutaneous route through which insulin is presented to the body in a non-physiological manner having many challenges. Hence novel approaches for insulin delivery are being explored. Challenges to oral route of insulin administration are: rapid enzymatic degradation in the stomach, inactivation and digestion by proteolytic enzymes in the intestinal lumen and poor permeability across intestinal epithelium because of its high molecular weight and lack of lipophilicity. Liposomes, microemulsions, nanocubicles, and so forth have been prepared for the oral delivery of insulin. Chitosan-coated microparticles protected insulin from the gastric environment of the body and released intestinal pH. Limitations to the delivery of insulin have not resulted in fruitful results to date and there is still a need to prepare newer delivery systems, which can produce dose-dependent and reproducible effects, in addition to increased bioavailability.

Insights into the Structural Features, Conformational Stability and Functional Activity of the Olneya tesota PF2 Lectin

2020 ◽  
Vol 27 ◽  
Author(s):  
Edgar Acedo-Espinoza ◽  
Irlanda Lagarda-Diaz ◽  
Rosina Cabrera ◽  
Ana M. Guzman-Partida ◽  
Amir Maldonado-Arce ◽  
...  
Keyword(s):  
Tertiary Structure ◽  
Proteolytic Enzymes ◽  
Conformational Stability ◽  
Structural Features ◽  
Beta Sheets ◽  
Hemagglutinating Activity ◽  
Effect Of Temperature ◽  
Hydrodynamic Diameter ◽  
Bioinformatic Tools ◽  
Structural Levels

Background: The O. tesota lectin PF2 is a tetrameric protein with subunits of 33 kDa that recognizes only complex carbohydrates, resistant to proteolytic enzymes and has insecticidal activity against Phaseolus beans pest. Objective: To explore PF2 lectin features at different protein structural levels and to evaluate the effect of temperature and pH on its functionality and conformational stability. Methods: PF2 lectin was purified by affinity chromatography. Its primary structure was resolved by mass spectrometry and analyzed by bioinformatic tools, including its tertiary structure homology modeling. The effect of temperature and pH on its conformational traits and stability was addressed by dynamic light scattering, circular dichroism, and intrinsic fluorescence. The hemagglutinating activity was evaluated using a suspension of peripheral blood erythrocytes. Results: The proposed PF2 folding comprises a high content of beta sheets. At pH 7 and 25 °C, the hydrodynamic diameter (Dh) was found to be 12.3 nm which corresponds to the oligomeric native state of PF2 lectin. Dh increased under the other evaluated pH and temperature conditions, suggesting protein aggregation. At basic pH, PF2 exhibited low conformational stability. The native PF2 (pH 7) retained its full hemagglutinating activity up to 45 °C and exhibited one transition state with a melting temperature of 76.8 °C. Conclusion: PF2 showed distinctive characteristics found in legume lectins. The pH influences the functionality and conformational stability of the protein. PF2 lectin displayed a relatively narrow thermostability to the loss of secondary structure and hemagglutinating activity.

Properties of proteolytic enzymes isolated from a thermophilic strain ofMicromonospora vulgaris 42

1976 ◽  
Vol 16 (5) ◽  
pp. 353-360 ◽  
Author(s):  
N. G. Nesterova ◽  
Yu. M. Khokhlova ◽  
L. G. Loginova ◽  
I. A. Tsaplina
Keyword(s):  
Proteolytic Enzymes
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