The Effects of Protein Charge Patterning on Complex Coacervation

2021 ◽  
Author(s):  
Nicholas Zervoudis ◽  
Allie Obermeyer
Keyword(s):  
Phase Boundary ◽  
Phase Behavior ◽  
Predictive Models ◽  
Phase Portraits ◽  
Complex Coacervation ◽  
Protein Encapsulation ◽  
Protein Charge ◽  
Polypeptide Sequence ◽  
The Impact ◽  
Coacervate Phase

The complex coacervation of proteins with other macromolecules has applications in protein encapsulation and delivery and for determining the function of cellular coacervates. Theoretical or empirical predictions for protein coacervates would enable the design of these coacervates with tunable and predictable structure-function relationships; unfortunately, no such theories exist. To help establish predictive models, the impact of protein-specific parameters on complex coacervation were probed in this study. The complex coacervation of sequence-specific, polypeptide-tagged, GFP variants and a strong synthetic polyelectrolyte was used to evaluate the effects of protein charge patterning on phase behavior. Phase portraits for the protein coacervates demonstrated that charge patterning dictates the protein’s binodal phase boundary. Protein concentrations over 100 mg mL<sup>-1</sup> were achieved in the coacervate phase, with concentrations dependent on the polypeptide sequence. In addition to shifting the binodal phase boundary, polypeptide charge patterning provided entropic advantages over isotropically patterned proteins. Together, these results show that modest changes of only a few amino acids alter the coacervation thermodynamics and can be used to tune the phase behavior of polypeptides or proteins of interest.

scholarly journals The Effects of Protein Charge Patterning on Complex Coacervation

2021 ◽  
Author(s):  
Nicholas Zervoudis ◽  
Allie Obermeyer
Keyword(s):  
Phase Boundary ◽  
Phase Behavior ◽  
Predictive Models ◽  
Phase Portraits ◽  
Complex Coacervation ◽  
Protein Encapsulation ◽  
Protein Charge ◽  
Polypeptide Sequence ◽  
The Impact ◽  
Coacervate Phase

The complex coacervation of proteins with other macromolecules has applications in protein encapsulation and delivery and for determining the function of cellular coacervates. Theoretical or empirical predictions for protein coacervates would enable the design of these coacervates with tunable and predictable structure-function relationships; unfortunately, no such theories exist. To help establish predictive models, the impact of protein-specific parameters on complex coacervation were probed in this study. The complex coacervation of sequence-specific, polypeptide-tagged, GFP variants and a strong synthetic polyelectrolyte was used to evaluate the effects of protein charge patterning on phase behavior. Phase portraits for the protein coacervates demonstrated that charge patterning dictates the protein’s binodal phase boundary. Protein concentrations over 100 mg mL<sup>-1</sup> were achieved in the coacervate phase, with concentrations dependent on the polypeptide sequence. In addition to shifting the binodal phase boundary, polypeptide charge patterning provided entropic advantages over isotropically patterned proteins. Together, these results show that modest changes of only a few amino acids alter the coacervation thermodynamics and can be used to tune the phase behavior of polypeptides or proteins of interest.

The effects of protein charge patterning on complex coacervation

Soft Matter ◽  
2021 ◽  
Author(s):  
Nicholas A. Zervoudis ◽  
Allie C. Obermeyer
Keyword(s):  
Globular Proteins ◽  
Complex Coacervation ◽  
Protein Encapsulation ◽  
Protein Charge

Charge patterned polypeptides modulate the complex coacervation of globular proteins with polymers. These protein coacervates have applications in protein encapsulation and delivery and in determining the function of biomolecular condensates.

Impact of macromolecular crowding on RNA/spermine complex coacervation and oligonucleotide compartmentalization

Soft Matter ◽  
2018 ◽  
Vol 14 (3) ◽  
pp. 368-378 ◽  
Author(s):  
A. M. Marianelli ◽  
B. M. Miller ◽  
C. D. Keating
Keyword(s):  
Phase Behavior ◽  
Functional Properties ◽  
Macromolecular Crowding ◽  
Complex Coacervation ◽  
Complex Coacervate ◽  
The Impact

The impact of macromolecular crowding on both the phase behavior and functional properties of complex coacervate droplets is explored.

scholarly journals Relationship between dental and periodontal health status and the salivary microbiome: bacterial diversity, co-occurrence networks and predictive models

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. Relvas ◽  
A. Regueira-Iglesias ◽  
C. Balsa-Castro ◽  
F. Salazar ◽  
J. J. Pacheco ◽  
...  
Keyword(s):  
Oral Health ◽  
Periodontal Disease ◽  
Bacterial Diversity ◽  
Predictive Models ◽  
Oral Disease ◽  
Rrna Gene ◽  
Convenience Sample ◽  
Core Microbiome ◽  
Rdna Sequencing ◽  
The Impact

AbstractThe present study used 16S rRNA gene amplicon sequencing to assess the impact on salivary microbiome of different grades of dental and periodontal disease and the combination of both (hereinafter referred to as oral disease), in terms of bacterial diversity, co-occurrence network patterns and predictive models. Our scale of overall oral health was used to produce a convenience sample of 81 patients from 270 who were initially recruited. Saliva samples were collected from each participant. Sequencing was performed in Illumina MiSeq with 2 × 300 bp reads, while the raw reads were processed according to the Mothur pipeline. The statistical analysis of the 16S rDNA sequencing data at the species level was conducted using the phyloseq, DESeq2, Microbiome, SpiecEasi, igraph, MixOmics packages. The simultaneous presence of dental and periodontal pathology has a potentiating effect on the richness and diversity of the salivary microbiota. The structure of the bacterial community in oral health differs from that present in dental, periodontal or oral disease, especially in high grades. Supragingival dental parameters influence the microbiota’s abundance more than subgingival periodontal parameters, with the former making a greater contribution to the impact that oral health has on the salivary microbiome. The possible keystone OTUs are different in the oral health and disease, and even these vary between dental and periodontal disease: half of them belongs to the core microbiome and are independent of the abundance parameters. The salivary microbiome, involving a considerable number of OTUs, shows an excellent discriminatory potential for distinguishing different grades of dental, periodontal or oral disease; considering the number of predictive OTUs, the best model is that which predicts the combined dental and periodontal status.

A Framework for Analyzing the Impact of Missing Data in Predictive Models

2020 ◽  
Author(s):  
Fabiola Santore ◽  
Eduardo C. de Almeida ◽  
Wagner H. Bonat ◽  
Eduardo H. M. Pena ◽  
Luiz Eduardo S. de Oliveira
Keyword(s):  
Missing Data ◽  
Predictive Models ◽  
The Impact

scholarly journals Translating the fabrication of protein-loaded poly(lactic-co-glycolic acid) nanoparticles from bench to scale-independent production using microfluidics

2020 ◽  
Vol 10 (3) ◽  
pp. 582-593 ◽  
Author(s):  
Carla B. Roces ◽  
Dennis Christensen ◽  
Yvonne Perrie
Keyword(s):  
Particle Size ◽  
Glycolic Acid ◽  
Polymeric Nanoparticles ◽  
Physicochemical Characteristics ◽  
European Medicines Agency ◽  
Protein Encapsulation ◽  
Human Use ◽  
Rate Ratios ◽  
The Impact ◽  
Process Controls

AbstractIn the formulation of nanoparticles, poly(lactic-co-glycolic acid) (PLGA) is commonly employed due to its Food and Drug Administration and European Medicines Agency approval for human use, its ability to encapsulate a variety of moieties, its biocompatibility and biodegradability and its ability to offer a range of controlled release profiles. Common methods for the production of PLGA particles often adopt harsh solvents, surfactants/stabilisers and in general are multi-step and time-consuming processes. This limits the translation of these drug delivery systems from bench to bedside. To address this, we have applied microfluidic processes to develop a scale-independent platform for the manufacture, purification and monitoring of nanoparticles. Thereby, the influence of various microfluidic parameters on the physicochemical characteristics of the empty and the protein-loaded PLGA particles was evaluated in combination with the copolymer employed (PLGA 85:15, 75:25 or 50:50) and the type of protein loaded. Using this rapid production process, emulsifying/stabilising agents (such as polyvinyl alcohol) are not required. We also incorporate in-line purification systems and at-line particle size monitoring. Our results demonstrate the microfluidic control parameters that can be adopted to control particle size and the impact of PLGA copolymer type on the characteristics of the produced particles. With these nanoparticles, protein encapsulation efficiency varies from 8 to 50% and is controlled by the copolymer of choice and the production parameters employed; higher flow rates, combined with medium flow rate ratios (3:1), should be adopted to promote higher protein loading (% wt/wt). In conclusion, herein, we outline the process controls for the fabrication of PLGA polymeric nanoparticles incorporating proteins in a rapid and scalable manufacturing process.

scholarly journals Prebiotically-relevant low polyion multivalency can improve functionality of membraneless compartments

2020 ◽  
Author(s):  
Fatma Pir Cakmak ◽  
Saehyun Choi ◽  
McCauley O. Meyer ◽  
Philip C. Bevilacqua ◽  
Christine D. Keating
Keyword(s):  
Molecular Weight ◽  
Phase Separation ◽  
Structure Formation ◽  
Rna Structure ◽  
Salt Resistance ◽  
Origins Of Life ◽  
Complex Coacervation ◽  
The Impact ◽  
Local Ph

AbstractMultivalent polyions can undergo complex coacervation, producing membraneless compartments that accumulate ribozymes and enhance catalysis, and offering a mechanism for functional prebiotic compartmentalization in the origins of life. Here, we evaluated the impact of low, prebiotically-relevant polyion multivalency in coacervate performance as functional compartments. As model polyions, we used positively and negatively charged homopeptides with one to 100 residues, and adenosine mono-, di-, and triphosphate nucleotides. Polycation/polyanion pairs were tested for coacervation, and resulting membraneless compartments were analyzed for salt resistance, ability to provide a distinct internal microenvironment (apparent local pH, RNA partitioning), and effect on RNA structure formation. We find that coacervates formed by phase separation of the relatively shorter polyions more effectively generated distinct pH microenvironments, accumulated RNA, and preserved duplexes. Hence, reduced multivalency polyions are not only viable as functional compartments for prebiotic chemistries, but they can offer advantages over higher molecular weight analogues.

scholarly journals Theory and applications of new fractional-order chaotic system under Caputo operator

2021 ◽  
Vol 12 (1) ◽  
pp. 20-38
Author(s):  
Ndolane Sene
Keyword(s):  
Fractional Order ◽  
Chaotic System ◽  
Caputo Derivative ◽  
Phase Portraits ◽  
Chaotic Circuit ◽  
Chaotic Model ◽  
The Stability ◽  
The Impact ◽  
Schematic Circuit ◽  
Good Agreement

This paper introduces the properties of a fractional-order chaotic system described by the Caputo derivative. The impact of the fractional-order derivative has been focused on. The phase portraits in different orders are obtained with the aids of the proposed numerical discretization, including the discretization of the Riemann-Liouville fractional integral. The stability analysis has been used to help us to delimit the chaotic region. In other words, the region where the order of the Caputo derivative involves and where the presented system in this paper is chaotic. The nature of the chaos has been established using the Lyapunov exponents in the fractional context. The schematic circuit of the proposed fractional-order chaotic system has been presented and simulated in via Mutltisim. The results obtained via Multisim simulation of the chaotic circuit are in good agreement with the results with Matlab simulations. That provided the fractional operators can be applied in real- worlds applications as modeling electrical circuits. The presence of coexisting attractors for particular values of the parameters of the presented fractional-order chaotic model has been studied.

Factors Associated With Unplanned Acute Care Services for Patients With Newly Diagnosed Hematologic Malignancies

2021 ◽  
pp. 1197-1206
Author(s):  
Kai Zu ◽  
Kristina L. Greenwood ◽  
Joyce C. LaMori ◽  
Besa Smith ◽  
Tyler Smith ◽  
...  
Keyword(s):  
Acute Care ◽  
Predictive Models ◽  
Psychosocial Functioning ◽  
Predictive Accuracy ◽  
Care Utilization ◽  
Medical Complication ◽  
Quality Reporting ◽  
Care Services ◽  
Acute Care Services ◽  
The Impact

PURPOSE This study evaluated risk factors predicting unplanned 30-day acute service utilization among adults subsequent to hospitalization for a new diagnosis of leukemia, lymphoma, or myeloma. This study explored the prevalence of medical complications (aligned with OP-35 measure specifications from the Centers for Medicare & Medicaid Services [CMS] Hospital Outpatient Quality Reporting Program) and the potential impact of psychosocial factors on unplanned acute care utilization. METHODS This study included 933 unique patients admitted to three acute care inpatient facilities within a nonprofit community-based health care system in southern California from 2012 to 2017. Integrated comprehensive data elements from electronic medical records and facility oncology registries were leveraged for univariate statistics, predictive models constructed using multivariable logistic regression, and further exploratory data mining, with predictive accuracy of the models measured with c-statistics. RESULTS The mean age of study participants was 65 years, and 55.1% were male. Specific diagnoses were lymphoma (48.7%), leukemia (35.2%), myeloma (14.0%), and mixed types (2.1%). Approximately one fifth of patients received unplanned acute care services within 30 days postdischarge, and over half of these patients presented with one or more symptoms associated with the CMS medical complication measure. The predictive models, with c-statistics ranging from 0.7 and above for each type of hematologic malignancy, indicated good predictive qualities with the impact of psychosocial functioning on the use of acute care services ( P values < .05), including lack of consult for social work during initial admission (lymphoma or myeloma), history of counseling or use of psychotropic medications (lymphoma), and past substance use (myeloma). CONCLUSION This study provides insights into patient-related factors that may inform a proactive approach to improve health outcomes, such as enhanced care transition, monitoring, and support interventions.

scholarly journals Nonlinear Dynamic Analysis and Chaos Prediction of Grinding Motorized Spindle System

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Weitao Jia ◽  
Feng Gao ◽  
Yan Li ◽  
Wenwu Wu ◽  
Zhongwei Li
Keyword(s):  
Nonlinear Dynamic ◽  
High Speed ◽  
Chaotic Behavior ◽  
Nonlinear Dynamic Analysis ◽  
Phase Portraits ◽  
Impact Factors ◽  
Nonlinear Dynamic Model ◽  
Motorized Spindle ◽  
Spindle System ◽  
The Impact

The paper determines the impact factors of dynamics of a motorized spindle rotor system due to high speed: centrifugal force and bearing stiffness softening. A nonlinear dynamic model of the grinding motorized spindle system considering the above impact factors is constructed. Through system simulation including phase portraits and Poincaré map, the periodic behavior and chaotic behavior of the nonlinear grinding motorized spindle system are revealed. The threshold curve of chaos motion is obtained through the Melnikov method. The conclusion can provide a theoretical basis for researching deeply the dynamic behaviors of the grinding motorized spindle system.

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