Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:2.7.10.1 (ERK)
95,504 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Nontypeable Haemophilus influenzae (NTHI) is an important etiological agent of otitis media (OM) and of exacerbated chronic obstructive pulmonary diseases (COPD). Inflammation is a hallmark of both diseases. Interleukin-8 (IL-8), one of the important inflammatory mediators, is induced by NTHI and may play a significant role in the pathogenesis of these diseases. Our studies demonstrated that a soluble cytoplasmic fraction (SCF) from NTHI induced much greater IL-8 expression by human epithelial cells than did NTHI lipooligosaccharides and envelope proteins. The IL-8-inducing activity was associated with molecules of < or =3 kDa from SCF and was peptidase and lipase sensitive, suggesting that small lipopeptides are responsible for the strong IL-8 induction. Moreover, multiple intracellular signaling pathways were activated in response to cytoplasmic molecules. The results indicated that the p38 mitogen-activated protein kinase (MAPK) and Src-dependent Raf-1-Mek1/2-extracellular signal-regulated kinase mitogen-activated protein kinase (ERK MAPK) pathways are required for NTHI-induced IL-8 production. In contrast, the phosphatidylinositol 3-kinase (PI3K)-Akt pathway did not affect IL-8 expression, although this pathway was concomitantly activated upon exposure to NTHI SCF. The PI3K-Akt pathway was also directly activated by IL-8 and significantly inhibited by an antagonist of IL-8 receptors during NTHI stimulation. These results indicated that the PI3K-Akt pathway is activated in response to IL-8 that is induced by NTHI and may lead to other important epithelial cell responses. This work provides insight into essential molecular and cellular events that may impact on the pathogenesis of OM and COPD and identifies rational targets for anti-inflammatory intervention.
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PMID:Up-regulation of interleukin-8 by novel small cytoplasmic molecules of nontypeable Haemophilus influenzae via p38 and extracellular signal-regulated kinase pathways. 1450 Apr 70

Modified Candida rugosa and Pseudomonas cepacia lipase (CRL and PCL) were co-lyophilized with two pairs of synthetic diastereoisomeric amphiphiles, D- and L-2-(3-[bis-[3-(2,3,4,5,6-pentahydroxy-hexanoylamino)-propyl]-carbamoyl]-propionylamino)-pentanedioic acid didodecyl ester (D- and L-BIG2C12CA); D- and L-2-(2,3,4,5,6-pentahydroxy-hexanoylamino)-pentanedioic acid didodecyl ester (D- and L-2C12GE). Enzyme activities of the modified lipase in the transesterification in organic solvent were evaluated. Both pairs of the diastereoisomeric amphiphiles showed enhanced enzyme activity in the transacetylation between racemic sulcatol and isopropenyl acetate in diisopropyl ether, catalyzed by the PCL-co-lyophilizate, by 19-48 fold when compared to the native lipase lyophilized from buffer alone independent of the stereochemistry of the amphiphiles, while in the case of the CRL-co-lyophilizate only the L-BIG2C12CA showed enhanced enzyme activity in the transbutyrylation between racemic solketal and vinyl butyrate in cyclohexane as high as 68-78 fold.
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PMID:Stereochemistry of a diastereoisomeric amphiphile and the species of the lipase influence enzyme activity in the transesterification catalyzed by a lipase-co-lyophilizate with the amphiphile in organic media. 1467 13

The objective of this study was to find the optimal parameters for lipase-catalyzed methanolysis of triricinolein to produce 1,2(2,3)-diricinolein. Four different immobilized lipases were tested, Candida antarctica type B (CALB), Rhizomucor miehei (RML), Pseudomonas cepacia (PCL), and Penicillium roquefortii (PRL). n-Hexane and diisopropyl ether (DIPE) were examined as reaction media at three different water activities (a(w)), 0.11, 0.53, and 0.97. The consumption of triricinolein and the formation of 1,2(2,3)-diricinolein, methyl ricinoleate, and ricinoleic acid were followed for up to 48 h. PRL gave the highest yield of 1,2(2,3)-diricinolein. Moreover, this lipase showed the highest specificity for the studied reaction, i.e., high selectivity for the reaction with triricinolein but low for 1,2(2,3)-diricinolein. Recoveries of 93 and 88% DAG were obtained using PRL in DIPE at a(w) of 0.11 and 0.53, respectively. Further, NMR studies showed that a higher purity of the 1,2(2,3)-isomer vs. the 1,3-isomer was achieved at higher a(w) (88% at a(w) = 0.53), compared to lower a(w) (71% at a(w) = 0.11). The DAG obtained was acylated by the DAG acyltransferase from Arabidopsis thaliana. Therefore, this enzymatic product is a useful enzyme substrate for lipid biosynthesis. Accordingly, the use of PRL in DIPE at a(w) 0.53 is considered optimal for the synthesis of 1,2(2,3)-diricinolein from triricinolein.
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PMID:Lipase-catalyzed methanolysis of triricinolein in organic solvent to produce 1,2(2,3)-diricinolein. 1473 66

The aims of the present study were to examine the effect of magnolol on lipolysis in sterol ester (SE)-loaded 3T3-L1 preadipocytes and to determine the signaling mechanism involved. We demonstrate that magnolol treatment resulted in a decreased number and surface area of lipid droplets, accompanied by release of glycerol. The lipolytic effect of magnolol was not mediated by PKA based on the facts that magnolol did not induce an elevation of intracellular cAMP levels, and protein kinase A (PKA) inhibitor KT5720 did not block magnolol-induced lipolysis. Calcium/calmodulin-dependent protein kinase (CaMK) was involved in this signaling pathway, since magnolol-induced a transient rise of intracellular [Ca(2+)] and Ca(2+) influx across the plasma membrane, and CaMK inhibitor significantly abolished magnolol-induced lipolysis. Moreover, magnolol increased the relative levels of phosphorylated extracellular signal-related kinases (ERK1 and ERK2). In support of the involvement ERK, we demonstrated that magnolol-induced lipolysis was inhibited by PD98059, an inhibitor of mitogen-activated protein kinase kinase (MEK), and PD98059 reversed magnolol-induced ERK phosphorylation. Further, the relationship between CaMK and ERK was connected by the finding that CaMK inhibitor also blocked magnolol-induced ERK phosphorylation. Taken together, these findings suggest that magnolol-induced lipolysis is both CaMK- and ERK-dependent, and this lipolysis signaling pathway is distinct from the traditional PKA pathway. ERK phosphorylation is reported to enhance lipolysis by direct activation of hormone sensitive lipase (HSL), thus magnolol may likely activate HSL through ERK and increase lipolysis of adipocytes.
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PMID:Signaling pathway of magnolol-stimulated lipolysis in sterol ester-loaded 3T3-L1 preadipocyes. 1503 36

A series of sorbitol-containing polyesters were synthesized via a one-pot lipase-catalyzed condensation polymerization. Thin films were prepared by spin coating on silicon wafers and surfaces were analyzed by tapping mode atomic force microscopy and contact angle measurements. Surface morphologies and surface energies across the series of polyester films, including a poly(epsilon-caprolactone) (PCL) control were nearly indistinguishable. Biocompatibility of the sorbitol-containing polyester series was evaluated against a PCL control by measuring cell spreading and proliferation of a mouse fibroblast 3T3 cell line in vitro. Results confirmed that the sorbitol-containing polyester surfaces elicited cell behavior similar to the PCL control. These results establish the sorbitol-containing polyester series as a promising material for tissue engineering research and development.
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PMID:Biocompatibility of sorbitol-containing polyesters. Part I: Synthesis, surface analysis and cell response in vitro. 1504 9

The micro construction of poly(epsilon-caprolactone) (PCL) and poly(L-lactic acid) (PLLA) blend films fabricated by solution casting under microwave irradiation was investigated by selective enzymatic degradation and scanning electron microscopy (SEM). The results were totally different from the blends obtained by conventional methods. The blend was more homogeneous and the PCL continuous phase more compact as no spherulites and tiny zone separation were observed from the film surface and no PCL network was observed inside the film, and the degradation of a PCL plank by Pseudomonas lipase was significantly retarded. The distributed PLLA micro spheres were enlarged and amorphous. The thermal behavior of the blend by microwave heating revealed that PCL and PLLA underwent a melting process, which induced the variations of the PCL phase and PLLA spheres. The weight loss caused by degradation of the PCL/PLLA blend obtained by conventional methods (B50c) is greater than that of the blend obtained by microwave methods (B50m), which reflects the change in morphology from a loose PCL network (B50c) to a dense PCL plank (B50m).
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PMID:Micro construction of poly(epsilon-caprolactone)/poly(L-lactic acid) blend film by solution casting under microwave irradiation. 1546 59

A highly sensitive analytical method for evaluation of poly(L-lactide) (PLA), poly(epsilon-caprolactone) (PCL), poly(beta-hydroxybutyrate) (PHB), and poly(butylene succinate) (PBS) degradability was developed using coated cellulose paper, prepared by penetration and adhesion of these plastics into/onto the cellulose paper. Enzymatic degradability of the obtained plastic coated papers was evaluated using various commercial proteases and lipases. PLA coated paper was highly susceptible to subtilisin and mammalian enzymes, alpha-chymotrypsin, elastase and trypsin. To our knowledge, this is the first report on the degradation of PLA coated paper using subtilisin and mammalian enzymes. Almost all lipase preparations degraded PCL and PHB coated papers but not PBS coated paper. The biodegradability of plastic coated paper was greater than that of plastic powder. The penetration of plastic into cellulose paper by coating improved the plastic degradability, and can be regulated easily.
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PMID:A new method for the evaluation of biodegradable plastic using coated cellulose paper. 1546 96

Poly(L-lactide) (PLLA) and poly(epsilon-caprolactone) (PCL) ultrafine fibers were prepared by electrospinning. The influence of cationic and anionic surfactants on their enzymatic degradation behavior was investigated by measuring weight loss, molecular weight, crystallinity, and melting temperature of the fibers as a function of degradation time. Under the catalysis of proteinase K, the PLLA fibers containing the anionic surfactant sodium docecyl sulfate (SDS) exhibited a faster degradation rate than those containing cationic surfactant triethylbenzylammonium chloride (TEBAC), indicating that surface electric charge on the fibers is a critical factor for an enzymatic degradation. Similarly, TEBAC-containing PCL fibers exhibited a 47% weight loss within 8.5 h whereas SDS-containing PCL fibers showed little degradation in the presence of lipase PS. By analyzing the charge status of proteinase K and lipase PS under the experimental conditions, the importance of the surface charges of the fibers and their interactions with the charges on the enzymes were revealed. Consequently, a "two-step" degradation mechanism was proposed: (1) the enzyme approaches the fiber surface; (2) the enzyme initiates hydrolysis of the polymer. By means of differential scanning calorimetry and wide-angle X-ray diffraction, the crystallinity and orientation changes in the PLLA and PCL fibers during the enzymatic degradation were investigated, respectively.
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PMID:Enzymatic degradation of poly(L-lactide) and poly(epsilon-caprolactone) electrospun fibers. 1558 89

According to our "block-copolymer-free" strategy for self-assembly of polymers, noncovalently connected micelles (NCCM) with poly(epsilon-caprolactone) (PCL) as the core and poly(acrylic acid) (PAA) as the shell in aqueous solutions were attained due to specific interactions between the component polymers. The micellar structure was then locked in by the reaction of PAA with diamine. Afterward, hollow spheres based on PAA network were obtained by either core degradation with lipase or core dissolution with dimethylformamide of the cross-linked micelles. The cavitation process was monitored by dynamic light scattering, which indicated a mass decrease and size expansion. The hollow structure is confirmed by transmission electron microscopy observations. The resultant hollow spheres are pH- and salt-responsive: there is a substantial volume increase when pH changes from acid to base, and vice versa. The volume change takes place dramatically over the pH-range from 5.8 to 7.5. Furthermore, this volume-pH-dependence is found to be completely reversible provided the effect of ionic strength is excluded. The volume change can be adjusted by changing the shell thickness and the cross-linking degree of the hollow spheres. The salt effect on the hollow sphere size depends on pH: with increasing salt concentration the size shows an increase, a decrease, and a little change in acidic, basic, and neutral media, respectively.
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PMID:pH-responsive core-shell particles and hollow spheres attained by macromolecular self-assembly. 1569 4

Random copolymers were prepared by Candida antarctica lipase B (Novozyme-435) catalyzed copolymerization of omega-pentadecalactone (PDL) with epsilon-caprolactone (CL). Over the whole composition range PDL-CL copolymers are highly crystalline (melting enthalpy by differential scanning calorimetry, above 100 J/g; crystallinity degree by wide-angle X-ray scattering, WAXS, 60-70%). The copolymers melt at temperatures that linearly decrease with composition from that of poly(omega-pentadecalactone) (PPDL; 97 degrees C) to that of poly(epsilon-caprolactone) (PCL; 59 degrees C). The WAXS profiles of PCL and PPDL homopolymers are very similar, except for the presence in PPDL of the (001) reflection at 2theta = 4.58 degrees that corresponds to a 19.3 angstroms periodicity in the chain direction. In PDL-CL copolymers the intensity of this reflection decreases with increasing content of CL units and vanishes at 50 mol % CL, as a result of randomization of the ester group alignment and loss of chain periodicity. PDL-CL copolymers crystallize in a lattice that gradually changes from that of one homopolymer to that of the other, owing to comonomer isomorphous substitution. Cocrystallization of comonomer units is also shown by a random PDL-CL copolymer obtained in a polymerization/transesterification reaction catalyzed by C. antarctica lipase B (Novozyme-435) starting from preformed PCL and PDL monomer.
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PMID:Cocrystallization of random copolymers of omega-pentadecalactone and epsilon-caprolactone synthesized by lipase catalysis. 1576 58


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