Design of PG-Surfactants Bearing Polyacrylamide Polymer Chain to Solubilize Membrane Proteins in a Surfactant-Free Buffer.

The development of techniques capable of using membrane proteins in a surfactant-free aqueous buffer is an attractive research area, and it should be elucidated for various membrane protein studies. To this end, we examined a method using new solubilization surfactants that do not detach from membrane protein surfaces once bound. The designed solubilization surfactants, DKDKC12K-PAn (n = 5, 7, and 18), consist of two parts: one is the lipopeptide-based solubilization surfactant part, DKDKC12K, fand the other is the covalently connected linear polyacrylamide (PA) chain with different Mw values of 5, 7, or 18 kDa. Intermolecular interactions between the PA chains in DKDKC12K-PAn concentrated on the surfaces of membrane proteins via amphiphilic binding of the DKDKC12K part to the integral membrane domain was observed. Therefore, DKDKC12K-PAn (n = 5, 7, and 18) could maintain a bound state even after removal of the unbound by ultrafiltration or gel-filtration chromatography. We used photosystem I (PSI) from Thermosynecoccus vulcanus as a representative to assess the impacts of new surfactants on the solubilized membrane protein structure and functions. Based on the maintenance of unique photophysical properties of PSI, we evaluated the ability of DKDKC12K-PAn (n = 5, 7, and 18) as a new solubilization surfactant.

Atypical Sensory Processing Profiles and Their Associations With Motor Problems In Preschoolers With Developmental Coordination Disorder.

The aims of this study were to identify sensory processing profiles specific to preschoolers with DCD in a community sample and examine the association of sensory processing problems with motor coordination difficulties in these children. Sixty-three 5-year-old children with DCD and without other neurodevelopmental disorders and 106 age-matched typically developing children participated in this study. Sensory processing problems were assessed using the Sensory Profile. Our results demonstrated problems in wide sensory processing patterns (low registration, sensitivity and avoiding) and areas (auditory, vestibular, touch and oral) in children with DCD compared with typically developing children. Additionally, the association of problems in sensory processing patterns (sensitivity and avoiding) and areas (touch and auditory) with motor coordination difficulties were identified in children with DCD alone. Our findings indicate that sensory processing abnormalities may contribute to the pathophysiology of DCD, suggesting the importance of assessing sensory processing functions in children with DCD.

Development of Cell-Penetration PG-Surfactants and Its Application in External Peptide Delivery to Cytosol.

Recently, development of techniques to deliver pharmacologically active biomacromolecules such as peptides and proteins to cytosol has gained much interest. Here, we applied the peptide gemini (PG)-surfactants to a novel platform to design cell penetration lipopeptides (CP-PGs), which can deliver exogenous peptides and proteins to cytosol. Among the number of candidate CP-PGs having different peptide sequences at the X-, Y-, and Z-positions, we focused on those having two C12 alkyl chains appended to the side chain of two Cys residues, the betaine sequence -Asp-Lys-Asp-Lys- between the alkylated Cys residues (i.e., at the X-position), and having different cationic peptide sequences of oligo-Lys or oligo-Arg at the Y- and/or Z-positions. With respect to cytotoxicity for mammalian cells such as NIH3T3 cells upon 1 h exposure, those having (Lys)3 (K3-DKDKC12 and DKCK12-K3) showed lower cytotoxicity (IC50 = 241 and 198 µM) among those having oligo-Lys, (Lys)n (n = 1, 3, 5; IC50 = 88-197 µM). Similar lower cytotoxicity was also observed for the CP-PG having two (Lys)3 at both N- and C-terminal sides (K3-DKDKC12-K3) (IC50 = 225 µM). In contrast, the CP-PG having (Arg)3 at the N-terminal side (R3-DKDKC12) showed higher cytotoxicity (IC50 = 88 µM). Carrier abilities of the CP-PGs for exogenous peptides were evaluated using the proapoptotic domain (PAD) peptide, which induces apoptosis by disturbing mitochondrial membranes after delivery into cytosol. As a result, the CP-PGs of K3-DKDKC12, DKCK12-K3, K3-DKDKC12-K3, DKCK12-K5, and R3-DKDKC12 exhibited micromolar range carrier ability (the necessary half concentration to induce cell death (EC50) by delivering PAD peptide to cytosol was 10, 6.2, 8.5, 5.8, and 11.5 µM, respectively). Especially, the carrier abilities of DKCK12-K3 and DKCK12-K5 were superior to the well-established cell penetration Arg-rich R8 peptide (EC50 = 6.8 µM). Together, our results indicate that the PG-surfactant molecular framework could be a potential new platform to design efficient cell penetration carrier materials.

Effects of voluntary and forced exercises on motor function recovery in intracerebral hemorrhage rats.

Motor paralysis is a severe consequence of intracerebral hemorrhage (ICH) that reduces patient quality of life. Rehabilitation is beneficial for stroke patients. However, functional recovery depends on the exercise type, and which factors are effective during rehabilitation are unknown. We aimed to clarify the effect of voluntary and forced exercises for functional recovery in ICH rats. Male Sprague-Dawley rats were divided into three groups: forced treadmill running (F-Ex.), voluntary wheel cage running (V-Ex.) and no exercise (Non-Ex.). The effects of the two exercises on motor recovery were analyzed by determining the motor deficit score and using the beam walking test. Stress and motivation status after rehabilitation were determined by corticosterone concentrations (ELISA) and immunoreactivity of ΔFosB (immunohistochemistry) in the nucleus accumbens, respectively. Significantly enhanced motor functional recovery was observed in the two trained groups compared with that in the Non-Ex. group. Of note, recovery in the V-Ex. group was greater than that in the F-Ex. group. To investigate the motivation and stress related to the exercises, the expression of ΔFosB in the nucleus accumbens and corticosterone concentration were compared after rehabilitation. In the V-Ex. group, there was a significant increase of ΔFosB, and in the F-Ex. Group, there was a high concentration of corticosterone. These data suggest that the effect of training for motor recovery was enhanced by motivation and reduced by stress.

Ultrasound irradiation before high-load exercise reduces muscle rigidity associated with delayed-onset muscle soreness.

[Purpose] We investigated the occurrence of delayed-onset muscle soreness and the suppression of muscle rigidity by ultrasound irradiation before high-load exercise. [Participants and Methods] The study was a randomized crossover controlled trial. The participants were 28 healthy university students (12 males, 16 females). Delayed-onset muscle soreness was induced in the biceps brachii muscle; ultrasound (3 MHz, 1.5 W/cm2, 10 min) was applied before high-load exercise. Pain during elbow motion was evaluated on a visual analog scale. Muscle rigidity was evaluated using a muscle rigidity meter. [Results] After exercise on the second day, the ultrasound group showed significantly less muscle rigidity. [Conclusion] The heat stimulus of ultrasound therapy before high-load exercise reduces muscle rigidity.

Development of New Antimicrobial Agents from Cationic PG-Surfactants Containing Oligo-Lys Peptides.

Peptide gemini-surfactant (PG-surfactant), a kind of lipopeptide, is composed of a short linker peptide (X) between two alkyl-chain-modified Cys residues and peripheral peptides at the N-terminal (Y) and the C-terminal (Z) sides, respectively, of the alkylated Cys residues. In this study, we developed and examined a series of PG-surfactants containing two C12 saturated alkanes and oligo-Lys, arranged at the X-, Y-, or Z-positions. To arrange oligo-Lys at the Y- or Z-positions, a repeat sequence of -Asp-Lys-Asp-Lys- was used at the X-position. All of the PG-surfactants exhibited high antimicrobial activity against both Gram-positive and -negative bacteria. In addition to high antimicrobial activity, a low hemolysis activity is prerequisite for efficient intravenous administration. Among the synthesized PG-surfactants, those having -(Lys)3- at the Y- or Z-positions, i.e. K3-DKDKC12 and DKDKC12K3, showed reasonably low hemolytic activities. This combination of high antimicrobial activity along with low hemolytic activity is an essential and unique property and has not been previously reported for the synthesized lipopeptides. Further, using scanning electron microscopy (SEM) and N-phenyl-1-naphthylamine (NPN) uptake assay we showed that the antimicrobial activity of these PG-surfactants may be attributed to membrane disruptive mechanisms. Although the PG-surfactants with low hemolytic activity could interact and localize onto red blood cell surfaces and cause slight expansion of cell morphologies, no subsequent penetration occurred. In summary, we describe here the successful development of PG-surfactants having high antibacterial and low hemolytic activity, thus providing a significant molecular platform to develop novel antimicrobial agents.

Construction of DNAzyme-Encapsulated Fibermats Using the Precursor Network Polymer of Poly(γ-glutamate) and 4-Glycidyloxypropyltrimethoxysilane.

Here, we developed functional nucleic acid (FNA)-encapsulated electrospun fibermats. To facilitate stable FNA encapsulation in the γ-PGA/GPTMS fibermats, we used the FNA as an FNA/streptavidin complex, and as a representative FNA, we selected a DNAzyme, the DNA/hemin complex, which is composed of G-quadraplex-forming single-stranded DNA and hemin and exhibits oxidation activity with the aid of a cocatalyst, H2O2. Scanning electron microscopy and Fourier-transform infrared spectroscopy measurements revealed that encapsulation of the DNA/hemin complex (∼1 wt % against the γ-PGA/GPTMS hybrid) in the nanofibers of the γ-PGA/GPTMS fibermats did not affect the structure of the original nanofibers. However, because a unique MW-dependent molecular permeability originated from the 3D network structure of the γ-PGA/GPTMS hybrid, low-MW substrates such as 4-aminoantipyrine, N-ethyl-N-(2-hydroxy-3-sulfopropyl)-3-methylaniline, and luminol were able to reach the encapsulated DNA/hemin complex by permeating to the inside of the nanofibers from an immersion buffer and then underwent catalytic oxidation. Conversely, nucleases, which are proteins featuring high MWs (>5 kDa), could not penetrate the γ-PGA/GPTMS nanofibers, and the encapsulated DNA/hemin complex was therefore effectively protected against nuclease digestion. Thus, encapsulating FNAs on the inside of the nanofibers of fibermats offers clear advantages for the practical application of FNAs in sensors and drugs, particularly for use in the in vivo circumstances.

Design of New Extraction Surfactants for Membrane Proteins from Peptide Gemini Surfactants.

The development of additional extraction surfactants for membrane proteins is necessary for membrane protein research, since optimal combinations for the successful extraction of target membrane proteins from biological membranes that minimize protein denaturation are hard to predict. In particular, those that have a unique basal molecular framework are quite attractive and highly desired in this research field. In this study, we successfully constructed a new extraction surfactant for membrane proteins, NPDGC12KK, from the peptide-gemini-surfactant (PG-surfactant) molecular framework. The PG-surfactant is a U-shaped lipopeptide scaffold, consisting of a short linker peptide (-X-) between two long alkyl-chain-modified Cys residues and a peripheral peptide (Y-) at the N-terminal side of long alkyl-chain-modified Cys residues. Using photosystem I (PSI) and photosystem II (PSII) derived from Thermosynecoccus vulcanus as representative membrane proteins, we evaluated whether NPDGC12KK could solubilize membrane proteins while maintaining structure and functions. Neither the membrane integral domain nor the cytoplasmic domain of PSI and PSII suffered any damage upon the use of NPDGC12KK based on detailed photophysical measurements. Using thylakoid membranes of T. vulcanus as a representative biological membrane sample, we performed experiments to extract membrane proteins, such as PSI and PSII. Based on the extraction efficiency and maintenance of protein supramolecular structure established using clear native-PAGE analyses, we proved that NPDGC12KK functions as a novel class of peptide-containing extraction surfactants for membrane proteins.

Construction and Characterization of Protein-Encapsulated Electrospun Fibermats Prepared from a Silica/Poly(γ-glutamate) Hybrid.

Protein-encapsulated fibermats are an attractive platform for protein-based bioactive materials. However, the choice of methods is still limited and not applicable to a wide range of proteins. In this study, we studied new polymeric materials for constructing protein-encapsulated fibermats, in which protein molecules are encapsulated within the nanofibers of fibermats without causing deleterious changes to protein structure or function. We constructed a protein-encapsulated fibermat using the poly(γ-glutamate) (PGA)/(3-glycidyloxypropyl)-trimethoxysilane (GPTMS) hybrid as a precursor for electrospinning. Because the PGA/GPTMS hybrid is water-soluble, protein molecules can be added to the precursor in an aqueous solution, significantly enhancing protein stability. Polycondensation during electrospinning (in-flight polycondensation) makes the obtained fibermats water-insoluble, which stabilizes the fibermat structure such that it is resistant to degradation in aqueous buffer. The molecular structure of the PGA/GPTMS hybrid gives rise to unique molecular permeability, which alters the selectivity and specificity of biochemical reactions involving the encapsulated enzymes; lower molecular-weight (MW) substrates can permeate the nanofibers, promoting enzyme activity, but higher MW substrates such as inhibitor peptides cannot permeate the nanofibers, suppressing enzyme activity. We present an effective method of encapsulating bioactive molecules while maintaining their structure and function, increasing the versatility of electrospun fibermats for constructing various bioactive materials.

Improved underpants to reduce toileting problems in patients with poor standing balance.

[Purpose] We developed and assessed improved underpants allowing patients to easily and completely open the crotch by pulling upward a string on the back of the underpants while seated. [Subjects and Methods] Healthy subjects tested commercial open-crotch underpants for disabled people and our improved open-crotch underpants by opening the crotch while seated. Measurement parameters included the percentage of crotch opening and the degree of genital or anal exposure before and after opening the crotch, as well as fit. The percentage of crotch opening and the degree of genital or anal exposure were recorded with a digital camera, and fit was determined with a visual analog scale. The measurements for both types of underpants were then compared. [Results] The commercial underpants for disabled people allowed opening of the crotch while seated, but the exposure of the genital and anal areas was insufficient to allow waste elimination. The improved underpants allowed sufficient opening of the crotch while seated and adequately exposed the genital and anal areas. The fit score of the improved underpants was significantly better than that of the commercial underpants. [Conclusion] The improved open-crotch underpants may allow for more effective opening of the crotch while seated than commercial open-crotch underpants for disabled people.

Approaches for improving the toileting problems of hemiplegic stroke patients with poor standing balance.

[Purpose] Our objective was to evaluate the residual dynamic and static functionality in the sitting position of hemiplegic stroke patients who require help to pull their lower garments up and down during toileting. [Subjects and Methods] The subjects were 11 hemiplegic patients. We gathered data on the patients' motor paralysis, sensory capacity, lower extremity muscle strength, trunk control, ability to roll and sit up from a lying position, sitting balance, and ability to pull the lower garments up and down. We then compared 2 groups: those able to pull the lower garments up and down independently while standing (the "independent group"), and those who were unable to do so (the "non-independent group"). [Results] Though the non-independent group had severely and significantly reduced trunk control and abilities as a whole, there was no significant difference from the independent group in static and dynamic sitting balance. [Conclusion] We conclude that, to enable hemiplegic patients with poor standing balance to pull their lower garments up and down, it is necessary to do these maneuvers in a sitting, rather than a standing, position, or to develop garments that are easier to put on and take off.

Creation of cross-linked bilayer membranes that can incorporate membrane proteins from oligo-Asp-based peptide gemini surfactants.

We designed novel bilayer-forming amphiphiles based on the cyclic oligo-Asp-based peptide gemini (PG) surfactants cr-D2C12 and cr-D3C12, which consist of -Cys(Asp)nCys- (n = 2 or 3) as a core peptide and two Cys residues containing a dodecylamidomethyl group. Dynamic light scattering and transmission electron microscopy measurements revealed the formation of spherical bilayer membranes that could incorporate the light-harvesting antenna complex 2 (LH2) from Rhodopseudomonas acidophila . Furthermore, this proteoliposome-like conjugate could be assembled onto cationized glass and mica to form planar bilayer membranes incorporating LH2. Using atomic force microscopy, we observed LH2 protruding (ca. 1.2-1.5 nm) from flat terraces of the planar bilayer membranes formed from cr-D2C12 or cr-D3C12. Thus, our designed PG surfactants are a new class of bilayer-forming amphiphiles that may be applied to the study of various membrane proteins.

Application of peptide gemini surfactants as novel solubilization surfactants for photosystems I and II of cyanobacteria.

We designed novel peptide gemini surfactants (PG-surfactants), DKDKC12K and DKDKC12D, which can solubilize Photosystem I (PSI) of Thermosynecoccus elongatus and Photosystem II (PSII) of Thermosynecoccus vulcanus in an aqueous buffer solution. To assess the detailed effects of PG-surfactants on the original supramolecular membrane protein complexes and functions of PSI and PSII, we applied the surfactant exchange method to the isolated PSI and PSII. Spectroscopic properties, light-induced electron transfer activity, and dynamic light scattering measurements showed that PSI and PSII could be solubilized not only with retention of the original supramolecular protein complexes and functions but also without forming aggregates. Furthermore, measurement of the lifetime of light-induced charge-separation state in PSI revealed that both surfactants, especially DKDKC12D, displayed slight improvement against thermal denaturation below 60 °C compared with that using ß-DDM. This degree of improvement in thermal resistance still seems low, implying that the peptide moieties did not interact directly with membrane protein surfaces. By conjugating an electron mediator such as methyl viologen (MV(2+)) to DKDKC12K (denoted MV-DKDKC12K), we obtained derivatives that can trap the generated reductive electrons from the light-irradiated PSI. After immobilization onto an indium tin oxide electrode, a cathodic photocurrent from the electrode to the PSI/MV-DKDKC12K conjugate was observed in response to the interval of light irradiation. These findings indicate that the PG-surfactants DKDKC12K and DKDKC12D provide not only a new class of solubilization surfactants but also insights into designing other derivatives that confer new functions on PSI and PSII.