scholarly journals Polypeptide-participating complex nanoparticles with improved salt-tolerance as excellent candidates for intelligent insulin delivery

RSC Advances ◽  
2017 ◽  
Vol 7 (23) ◽  
pp. 14088-14098 ◽  
Author(s):  
Yuqiang Li ◽  
Yunyan Zhang ◽  
Junjiao Yang ◽  
Jing Yang
Keyword(s):  
Salt Tolerance ◽  
Salt Concentration ◽  
Insulin Delivery ◽  
Ordered Structures ◽  
Responsive Materials ◽  
Synthetic Polypeptides ◽  
Physiological Salt Concentration

The strategy of introducing synthetic polypeptides with hierarchical ordered structures into glucose-responsive materials is reported in this study to achieve self-regulated release of insulin under physiological salt concentration.

Circular dichroism of polypeptides

1967 ◽  
Vol 297 (1448) ◽  
pp. 163-170 ◽  
Keyword(s):  
Conformational Changes ◽  
Control Mechanisms ◽  
Ordered Structure ◽  
Ordered Structures ◽  
Naturally Occurring ◽  
Synthetic Polypeptides ◽  
Spectroscopic Characteristics ◽  
Physical Attributes ◽  
The Right ◽  
Polypeptide Conformation

The polypeptides, together with the polynucleotides, are polymers which possess the unique property, under the right conditions, of forming ordered structures in dilute isotropic solution. This general attribute is responsible for the precise specificity of structure, and consequently of biochemical function, of the naturally occurring proteins and nucleic acids in their most usual native environment, aqueous solution. It gives rise also to the possibility of extraordinarily delicate biological control mechanisms, based on the induction of conformational changes in the macromolecule by small alterations in the environment. The most versatile methods available for the study of polypeptide conformation in solution are without doubt the spectroscopic ones, and of these the measurement of optical activity is preeminent. The ordered structure of these molecules—and we shall consider here primarily the synthetic homopolyamino acids—makes it possible to regard them essentially as one dimensional unimolecular crystals, and indeed they possess a number of important physical attributes associated with the crystalline state. Thus the collapse of the ordered structure when the environment is changed commonly occurs in a sharp cooperative manner, recalling a crystalline phase transition (melting). More particularly the ordered system of chromophores (peptide groups) gives rise to certain of the spectroscopic characteristics of molecular crystals, and it is these phenomena which provide us with the principal means of studying synthetic polypeptides and proteins in solution. It is evident then that a better understanding of these effects will be of the greatest relevance to the study of conformations and conformational changes in these molecules.

scholarly journals Salt Tolerance of Three Tree Species Differing in Native Habitats and Leaf Traits

HortScience ◽  
2014 ◽  
Vol 49 (9) ◽  
pp. 1194-1200
Author(s):  
Nisa Leksungnoen ◽  
Roger K. Kjelgren ◽  
Richard C. Beeson ◽  
Paul G. Johnson ◽  
Grant E. Cardon ◽  
...  
Keyword(s):  
Salt Tolerance ◽  
Gas Exchange ◽  
Salt Concentration ◽  
Leaf Traits ◽  
Leaf Damage ◽  
Urban Landscapes ◽  
Salt Tolerant ◽  
Native Habitat ◽  
Saline Habitats ◽  
Salinity Levels

We investigated if salt tolerance can be inferred from observable cues based on a woody species’ native habitat and leaf traits. Such inferences could improve species selection for urban landscapes constrained by soils irrigated with reclaimed water. We studied the C3 tree species Acer grandidentatum Nutt. (canyon maple; xeric-non-saline habitat) that was hypothesized to have some degree of salt tolerance based on its semiarid but non-saline native habitat. We compared it with A. macrophyllum Pursh. (bigleaf maple) from mesic/riparian-non-saline habitats with much larger leaves and Eucalyptus camaldulensis Dehnh. (eucalyptus/red gum) from mesic-saline habitats with schlerophyllous evergreen leaves. Five levels of increasing salt concentrations (non-saline control to 12 dS·m−1) were applied over 5 weeks to container-grown seedling trees in two separate studies, one in summer and the other in fall. We monitored leaf damage, gas exchange, and hydric behavior as measures of tree performance for 3 weeks after target salinity levels were reached. Eucalyptus was the most salt-tolerant among the species. At all elevated salinity levels, eucalyptus excluded salt from its root zone, unlike either maple species. Eucalyptus maintained intact, undamaged leaves with no effect on photosynthesis but with minor reductions in stomatal conductance (gS). Conversely, bigleaf maple suffered increasing leaf damage, nearly defoliated at the highest levels, with decreasing gas exchange as salt concentration increased. Canyon maple leaves were not damaged and gas exchange was minimally affected at 3 dS·m−1 but showed increasing damage at higher salt concentration. Salt-tolerant eucalyptus and riparian bigleaf maple framed canyon maple’s moderate salt tolerance up to 3 dS·m−1 that appears related to seasonal soil drying in its semiarid native habitat. These results highlight the potential to infer a degree of salt tolerance from either native habitat or known drought tolerance in selecting plant species for urban landscapes limited by soil salinity or brackish irrigation water. Observable cues such as xeri-morphic leaf traits may also provide visual evidence of salt tolerance.

Salt Effects in Mucin Lubrication

1969 ◽  
Vol 91 (3) ◽  
pp. 371-373 ◽  
Author(s):  
C. W. McCutchen ◽  
J. F. Wilkins
Keyword(s):  
Salt Concentration ◽  
Entire Range ◽  
Good Evidence ◽  
Joint Fluid ◽  
Chain Polymer ◽  
Polymer Molecules ◽  
Lubricating Film ◽  
Joint Load ◽  
Long Chain ◽  
Physiological Salt Concentration

Animal joints are lubricated by two complementary mechanisms. Weeping lubrication carries most of the joint load hydrostatically, leaving only a small fraction of the total to be carried by rubbing of the solid “skeletons” of the two cartilages. This rubbing is, in turn, lubricated by the synovial mucin; i.e., by long chain polymer molecules dissolved in the joint fluid. There is good evidence that the mucin molecules adsorb to the surfaces and provide boundary lubrication. In this paper we examine further this adsorption processs using a bearing whose two surfaces are rubber and glass, respectively. It is found that the lubricating ability of the mucin is good if it is applied to the bearing in a solution with about physiological salt concentration. At higher salt concentrations the lubrication is comparatively poor, while at zero salt concentration it is very bad indeed. If, on the other hand, the mucin is applied at physiological salt concentration, and then the salt and unadsorbed mucin are washed away with distilled water the lubrication remains good, and has, on occasion, even improved. Once the mucin has been adsorbed the entire range of salt concentration can be explored, with the lubrication becoming worse at high salt concentration and then recovering in greater or lesser degree when the salt is washed off. It seems, then, that the salt concentration affects lubrication in two ways. It can upset the adsorption of the lubricating film, and it can change the lubricating effectiveness of the film once it is adsorbed.

scholarly journals Salt Tolerance Mechanism of the Rhizosphere Bacterium JZ-GX1 and Its Effects on Tomato Seed Germination and Seedling Growth

2021 ◽  
Vol 12 ◽  
Author(s):  
Pu-Sheng Li ◽  
Wei-Liang Kong ◽  
Xiao-Qin Wu
Keyword(s):  
Salt Stress ◽  
Salt Tolerance ◽  
Seedling Growth ◽  
Salt Concentration ◽  
High Salt ◽  
Stem Length ◽  
Tolerance Mechanism ◽  
Rhizosphere Bacterium ◽  
Moderately Halophilic Bacterium ◽  
Growth Promoting

Salinity is one of the strongest abiotic factors in nature and has harmful effects on plants and microorganisms. In recent years, the degree of soil salinization has become an increasingly serious problem, and the use of plant growth-promoting rhizobacteria has become an option to improve the stress resistance of plants. In the present study, the salt tolerance mechanism of the rhizosphere bacterium Rahnella aquatilis JZ-GX1 was investigated through scanning electron microscopy observations and analysis of growth characteristics, compatible solutes, ion distribution and gene expression. In addition, the effect of JZ-GX1 on plant germination and seedling growth was preliminarily assessed through germination experiments. R. aquatilis JZ-GX1 was tolerant to 0–9% NaCl and grew well at 3%. Strain JZ-GX1 promotes salt tolerance by stimulating the production of exopolysaccharides, and can secrete 60.6983 mg/L of exopolysaccharides under the high salt concentration of 9%. Furthermore, the accumulation of the compatible solute trehalose in cells as the NaCl concentration increased was shown to be the primary mechanism of resistance to high salt concentrations in JZ-GX1. Strain JZ-GX1 could still produce indole-3-acetic acid (IAA) and siderophores and dissolve inorganic phosphorus under salt stress, characteristics that promote the ability of plants to resist salt stress. When the salt concentration was 100 mmol/L, strain JZ-GX1 significantly improved the germination rate, germination potential, fresh weight, primary root length and stem length of tomato seeds by 10.52, 125.56, 50.00, 218.18, and 144.64%, respectively. Therefore, R. aquatilis JZ-GX1 is a moderately halophilic bacterium with good growth-promoting function that has potential for future development as a microbial agent and use in saline-alkali land resources.

scholarly journals Responsive Materials for Self-Regulated Insulin Delivery

2013 ◽  
Vol 13 (11) ◽  
pp. 1464-1477 ◽  
Author(s):  
Weitai Wu ◽  
Shuiqin Zhou
Keyword(s):  
Insulin Delivery ◽  
Responsive Materials

Detection of Transplant Rejection Chemokine Protein Biomarker in Physiological Salt Concentration

2013 ◽  
Vol 13 (2) ◽  
pp. 438-439 ◽  
Author(s):  
F. S. Tulip ◽  
E. Eteshola ◽  
S. Desai ◽  
S. Mostafa ◽  
S. Roopa ◽  
...  
Keyword(s):  
Salt Concentration ◽  
Transplant Rejection ◽  
Protein Biomarker ◽  
Physiological Salt Concentration

scholarly journals Identification of a Novel Salt-Tolerant Streptomyces Isolate with Bio-Fertilizing Property

2016 ◽  
Vol 1 (2) ◽  
pp. 116
Author(s):  
Rebah N. Algafari ◽  
Ibrahim I. Hasan ◽  
Ghayda A. Al-Joubory
Keyword(s):  
Salt Tolerance ◽  
Seed Germination ◽  
Salt Concentration ◽  
Salt Tolerant ◽  
Different Types ◽  
Germinating Seeds ◽  
Streptomyces Isolate

<p><em>A 65 local Streptomyces isolates were tested for their salt tolerance ability. Four of them were found to grow on 6% salt concentration medium. These were selected as candidates for bio-fertilizing use. Only one of them named Streptomyces NS-38 was found to pose such trait by enhancing accelerated seed germination of different types of plants on salt and normal media. Result showed that incubation of seeds with this bacterium extract for 15 hours before implantation increased the number of germinating seeds and yield significantly.</em></p>

Specific Cation Effects on Hemoglobin Aggregation below and at Physiological Salt Concentration

Langmuir ◽  
2013 ◽  
Vol 29 (49) ◽  
pp. 15350-15358 ◽  
Author(s):  
Luca Medda ◽  
Cristina Carucci ◽  
Drew F. Parsons ◽  
Barry W. Ninham ◽  
Maura Monduzzi ◽  
...  
Keyword(s):  
Salt Concentration ◽  
Cation Effects ◽  
Physiological Salt Concentration
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