Gene/Protein Disease Symptom Drug Enzyme Compound
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Amylase and lysozyme are components of the salivary pellicle, exposing considerable enzymatic activity in the immobilized state. The purpose of the present study was to elucidate the influence of different solid substrata on the amount and distribution of amylase and lysozyme exposed on the surface of the salivary pellicle formed in situ. Slabs of titanium, feldspar ceramic, and bovine enamel were fixed on the buccal sites of individual splints worn by three subjects for 3 or 30 min, respectively, to allow pellicle formation. Subsequently, slabs were removed from the splints and rinsed with running water. Detection of amylase and lysozyme was performed by FEI-SEM after gold-immunolabeling of the enzymes. Both enzymes were found to be distributed randomly at the pellicle surface. Irrespective of formation time and substratum, significantly more labeled lysozyme molecules (5.23 +/- 4.5 microm(-2)) were detected compared with amylase (3.4 +/- 2.9 microm(-2)). Neither the substratum nor the pellicle formation time had significant impact on the amount of the respective enzyme that could be detected. This study for the first time provides evidence, that amylase and lysozyme are exposed at the surface of the salivary pellicle formed in situ on titanium and ceramics. Both enzymes are distributed randomly on the surface of the pellicle, irrespective of the underlying substratum.
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PMID:Detection of salivary alpha-amylase and lysozyme exposed on the pellicle formed in situ on different materials. 1738 May 1

Mesoporous zirconium organophosphonates with a tunable mesopore (pore diameter: from 4.8 to 16.3 nm) were synthesized through co-condensation of ZrCl4 and 1-phosphomethylproline (H3PMP) with the aid of organic additives in the presence of an anionic surfactant (sodium dodecyl sulfate) under weak acidic conditions. The organic additives, tetrahydrofuran, can effectively strengthen the assembly of ZrCl4 and H3PMP around the surfactant micelles through decreasing the hydrolysis and condensation rate of ZrCl4. The results of the N2 sorption isotherm and SEM image show that zirconium phosphate with a bimodal structure is formed by calcination of mesoporous zirconium organophosphonate. Mesoporous zirconium organophosphonates can effectively adsorb lysozyme (Lz) and papain, and the adsorption equilibrium for Lz can be reached within 30 min. The adsorption capacity for Lz and papain can reach as high as 438 and 297 mg/g, respectively. Furthermore, Lz adsorbed on mesoporous zirconium organophosphonates can retain its structural conformation as in its free state, and no leaching of Lz from the solid was observed when shaking the Lz-loaded solid in a buffer solution. Also, the existence of L-proline in the mesopore could help the adsorption of papain at a pH value lower than the pI of papain.
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PMID:Pore-size tunable mesoporous zirconium organophosphonates with chiral L-proline for enzyme adsorption. 1769 27

The design, synthesis and properties of a new class of enzyme/DNA/inorganic nanobiomaterials are described here. DNA has been used to stabilize the enzymes intercalated in the galleries of the inorganic solid, alpha-Zr(iv) phosphate (alpha-Zr(HPO(4))(2).H(2)O, abbreviated as alpha-ZrP). Interestingly, the presence of DNA improved the activity and stability of the bound enzymes. Key studies leading to the current strategy are presented initially, and these are followed by more recent developments. Several enzymes and proteins, including horseradish peroxidase, lysozyme, glucose oxidase, chymotrypsin, bovine serum albumin, cytochrome c, met-hemoglobin and met-myoglobin are successfully intercalated in the galleries of alpha-ZrP, under benign ambient conditions (aqueous buffered solutions, at room temperature and neutral pH). These novel materials are characterized by XRD, SEM and TEM as well as by biochemical, calorimetric and spectroscopic methods. Spectroscopic studies (circular dichroism, CD), for example, indicated that co-intercalation of DNA improved the retention of bound enzyme structure. The activity was enhanced markedly (five-fold) when DNA is co-intercalated, when compared to the activity in the absence of DNA. Addition of DNA to the sample, after enzyme intercalation, did not make any improvements. Our hypothesis is that enzyme-DNA supramolecular complex binds to the solid and the unfavorable interactions between the enzyme and the solid are minimized. These novel nanobiocomposite materials provide a simple method for packaging DNA and aid in engineering more effective synthetic materials for gene/RNA-delivery and drug delivery applications.
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PMID:Novel enzyme/DNA/inorganic nanomaterials: a new generation of biocatalysts. 1804 9

Amyloids are pathological fibrillar aggregates of proteins related to more than 20 different diseases. Amyloid fibers have a characteristic cross-beta structure consisting of a series of beta-strands extended perpendicular to the fiber axis and joined by hydrogen bonds parallel to the fiber direction. Fibril aggregation results in helical suprastructures. Here we used high-resolution SEM and cryo-SEM for the study of chirality in the amyloid suprastructure. We found that amyloids of Abeta1-40 and hen lysozyme form at all hierarchical levels always and only left-handed helices. In contrast, amyloid fibers formed by the N-terminal sequence of serum amyloid A (SAA1-12) consist of right-handed helices exclusively. Consistently, the peptide enantiomer, formed of (R)-aminoacids, aggregates exclusively in left-handed helices. We conclude that the opposite handedness of the SAA1-12 amyloids is an intrinsic feature of the peptide structure. The left-handed chirality observed for the Abeta1-40 and hen lysozyme amyloid suprastructures is consistent with the conventional beta-sheet structural model. In contrast, the right-handedness observed in (all-S) SAA1-12 fibers indicates that the cross-beta structure of SAA1-12 fibers is probably not formed of beta-sheets. Whatever the answer to the dilemma of the right-handed helicity of SAA1-12 amyloid fibers is, its existence shows that the supramolecular chirality of amyloid fibers is not only dictated by the molecular chirality of the component molecules but also by their structural organization.
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PMID:Chirality of amyloid suprastructures. 1833 97

In this report, a four-component nanocomposite, trypsin-immobilized polyaniline-coated Fe(3)O(4)/carbon nanotube composite, was synthesized for highly efficient protein digestion. Fe(3)O(4) was deposited by the chemical coprecipitation of Fe(2+) and Fe(3+) in an alkaline solution containing carbon nanotubes (CNTs) to prepare nano-Fe(3)O(4)/CNT composite. Subsequently, polyaniline (PA) was assembled on the Fe(3)O(4)/CNT composite by the in situ polymerization of aniline in the presence of trypsin to obtain trypsin-immobilized PA/Fe(3)O(4)/CNT nanocomposite. The novel 1D superparamagnetic biomaterial has been characterized by TEM, SEM, XRD, and magnetometric analysis. The feasibility and performance of the unique magnetic biomaterial have been demonstrated by the tryptic digestion of bovine serum albumin, myoglobin, and lysozyme within 5min. The digests were identified by MALDI-TOF MS with sequence coverages that were comparable to those obtained from the conventional in-solution tryptic digestion. The present biocomposite offers considerable promise for protein analysis due to its high magnetic responsivity and excellent dispersibility. It can be easily isolated from the digests with the aid of an external magnetic field. Because the enzyme-immobilized nanocomposite can be prepared by a simple two-step deposition approach at low cost, it may find a wide range of biological applications including proteome research.
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PMID:Immobilization of trypsin in polyaniline-coated nano-Fe3O4/carbon nanotube composite for protein digestion. 1835 64

Lysozyme, a major component of egg white proteins, has been speculated to participate in the calcification of avian eggshells. However, its detailed role during the eggshell formation is not well understood. In this work, the influence of lysozyme on the precipitation of CaCO(3) has been investigated using a combined study of FTIR, XRD, and SEM. The precipitation was produced from (NH(4))(2)CO(3) vapor diffusion into CaCl(2) aqueous solution using a specially built chamber. In the absence of lysozyme, hexagonal platelets of vaterite and their spherical aggregates dominated the precipitates during the first 3-12 h crystallization period studied, with the (001) crystal face well expressed in the hexagonal direction. In contrast, calcite was favored to precipitate in the presence of lysozyme during the same period and the effect was found to be proportional to lysozyme concentration. Furthermore, the (110) face of calcite was expressed in addition to the common (104) face, and the morphological modification was also lysozyme concentration dependent. We attributed these phenomena to the selective adsorption of ammonium ions and lysozyme onto different crystal faces. Our findings have clearly revealed the concentration and face dependent role of lysozyme in CaCO(3) precipitation. This, together with the abundance of lysozyme in the uterine fluid, implies its direct contribution to the hierarchical structures of calcite during the initial stage of eggshell formation.
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PMID:Lysozyme mediated calcium carbonate mineralization. 1916 7

Since the discovery of ordered mesoporous silica M41S in 1992, a variety of ordered mesoporous materials have been synthesized by using the template technique. In this work, aminosilane-modified SBA-15 nanoparticles were prepared by incorporating various aminosilanes on original SBA-15 via post synthesis method. These aminosilanes were 3-aminopropyltriethoxysilane, N-2(-aminoethyl)-3-aminopropyl trimethoxysilane and (3-trimethoxysilylpropyl)diethylenetriamine. The synthesized nanoparticles were characterized by XRD, SEM, TEM and FT-IR. Adsorption and release studies of bovine serum albumin (BSA), lysozyme and myoglobin on SBA-15 samples were investigated. It was found that the synthesized SBA-15 nanoparicles can be successfully applied in drug delivery system.
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PMID:Adsorption properties of proteins on SBA-15 nanoparticles functionalized with aminosilanes. 1919 10

A model considering the overall axial dispersion for describing protein adsorption and breakthrough in monolithic cryogel beds has been developed. The microstructure of cryogels was characterized by tortuous capillaries with a normal diameter distribution but a constant pore wall thickness. The axial dispersion within cryogel columns was described by using the overall axial dispersion coefficient, which can be easily obtained by matching the experimental breakthrough curves without adsorption or measuring residence time distributions (RTDs). Experimental breakthrough curves of lysozyme within a metal-chelated affinity cryogel by Persson et al. (Biotechnol. Bioeng. 2004, 88, 224-236) and a cation-exchange cryogel by Yao et al. (J. Chromatogr. A 2007, 1157, 246-251) were employed as examples to test the model. The results showed that by using the axial dispersion coefficient and assuming uniform radial concentration profile at a given cross-section of the cryogel along the bed height, the model can describe the detailed behaviors of the in-bed overall axial dispersion, the in-pore mass transfer, as well as the protein adsorption and breakthrough. For a known overall axial dispersion coefficient, the lumped parameter of the mass transfer coefficient between the bulk liquid and the capillary wall can be determined by fitting the protein breakthrough curve at a known chromatographic condition. Once this parameter is determined, the model can be used to predict the protein breakthrough profiles under different conditions based on the basic physical parameters of the cryogel bed and the properties of the fluid and protein. The effective capillary diameters employed in the model are close to the actual pore sizes observed from the images by SEM. The model predictions of lysozyme breakthrough profiles at various flow rates are also in good agreement with the experimental data in both the metal-chelated affinity and cation-exchange cryogel columns.
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PMID:Modeling of protein breakthrough performance in cryogel columns by taking into account the overall axial dispersion. 1963 9

An injectable hydrogel for chondrocyte delivery was developed by blending chitosan and starch derived from various sources with beta-glycerol phosphate (beta-GP) in the expectation that it would retain a liquid state at room temperature and gel at raised temperatures. Rheological investigation indicated that the system consisting of chitosan derived from crab shell and corn starch at 4:1 by weight ratio (1.53%, w/v of total polymers), and 6.0% (w/v) beta-GP (C/S/GP system) exhibited the sharpest sol-gel transition at 37+/-2 degrees C. The C/S/GP hydrogel was gradually degraded by 67% within 56 days in PBS containing 0.02 mg/ml lysozyme. The presence of starch in the system increased the water absorption of the hydrogel when compared to the system without starch. SEM observation revealed to the interior structure of the C/S/GP hydrogel having interconnected pore structure (average pore size 26.4 microm) whereas the pore size of the hydrogel without starch was 19.8 microm. The hydrogel also showed an ability to maintain chondrocyte phenotype as shown by cell morphology and expression of type II collagen mRNA and protein. In vivo study revealed that the gel was formed rapidly and localized at the injection site.
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PMID:Potential of an injectable chitosan/starch/beta-glycerol phosphate hydrogel for sustaining normal chondrocyte function. 2020 48

As a major constituent of egg white matrix, ovalbumin has long been perceived to be implicated in the formation of avian eggshells, in particular, the mammillary layer. However, very little is known about the detailed mechanism by which this protein mediates shell calcification. By the combined studies of AFM, SEM, and TEM, we have investigated the influence of ovalbumin on CaCO(3) precipitation under in vitro mineralization conditions. We observed that the influence was multifold. This protein modified the morphology of calcite crystals through a distinct anisotropic process with respect to the four crystal step edges. AFM characterization revealed that the modification was initiated at the obtuse-obtuse step corner and propagated predominantly along the obtuse steps. Furthermore, the protein favored the existence of unstable phases such as amorphous calcium carbonate and crystalline vaterite. In contrast, lysozyme, another protein also present in the system, played a very different role in modifying calcite morphology. The mechanistic understanding gained from this study is clearly also of practical significance in developing advanced inorganic CaCO(3) materials with the aid of morphological manipulation of crystalline structures via different protein mediation.
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PMID:Influence of ovalbumin on CaCO3 precipitation during in vitro biomineralization. 2036 64


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