Consideration on Efficient Recombinant Protein Production: Focus on Substrate Protein-Specific Compatibility Patterns of Molecular Chaperones

The Protein Journal - Expression of recombinant proteins requires at times the aid of molecular chaperones for efficient post-translational folding into functional structure. However, predicting...     

Azole-resistant Aspergillus fumigatus is highly prevalent in the environment of Vietnam,with marked variability by land use type

Azole-resistant environmental Aspergillus fumigatus presents a threat to public health but the extent of this threat in Southeast Asia is poorly described. We conducted environmental surveillance in the Mekong Delta region of Vietnam, collecting air and ground samples across key land-use types, and determined antifungal susceptibilities of Aspergillus section Fumigati (ASF) isolates and azole concentrations in soils. Of 119 ASF isolates, 55% were resistant (or non-wild type) to itraconazole, 65% to posaconazole and 50% to voriconazole. Azole resistance was more frequent in A. fumigatus sensu stricto isolates (95%) than other ASF species (32%). Resistant isolates and agricultural azole residues were overrepresented in samples from cultivated land. cyp51A gene sequence analysis showed 38/56 resistant A. fumigatus sensu stricto isolates carried known resistance mutations, with TR₃₄/L98H most frequent (34/38).     

Bilateral impairments of shoulder abduction in chronic hemiparesis: Electromyographic patterns and isokinetic muscle performance

ObjectiveTo analyze electromyographic (EMG) patterns and isokinetic muscle performance of shoulder abduction movement in individuals who sustained a cerebrovascular accident (CVA).DesignTwenty-two individuals who sustained a CVA and 22 healthy subjects volunteered for EMG activity and isokinetic shoulder abduction assessments. EMG onset time, root mean square (RMS) for upper trapezius and deltoid muscles, as well as the isokinetic variables of peak torque, total work, average power and acceleration time were compared between limbs and groups.ResultsThe paretic side showed a different onset activation pattern in shoulder abduction, along with a lower RMS for both muscles (21.8 ± 13.4% of the maximal voluntary isometric contraction (MVIC) for the deltoid and 25.9 ± 15.3% MVIC for the upper trapezius, about 50% lower than the control group). The non-paretic side showed a delay in both muscles activation and a lower RMS for the deltoid (32.2 ± 13.7% MVIC, about 25% lower than the control group). Both sides of the group of individuals who sustained a CVA presented a significantly lower isokinetic performance compared to the control group (paretic side ～60% lower; non-paretic side ～35% lower).ConclusionsShoulder abduction muscle performance is impaired in both paretic and non-paretic limbs of individuals who sustained a CVA.     

Correction for Irrelevant Absorption in Multicomponent Spectrophotometric Assay of Riboflavin, Formylmethylflavin, and Degradation Products: Kinetic Applications

In the spectrophotometric assay of multicomponent systems involved in drug degradation studies, some minor or unknown degradation products may be present. These products may interfere in the assay and thus invalidate the results due to their absorption in the range of analytical wavelengths. This interference may be eliminated by the application of an appropriate correction procedure to obtain reliable data for kinetic treatment. The present study is based on the application of linear and non-linear irrelevant absorption corrections in the multicomponent spectrophotometric assay of riboflavin and formylmethylflavin during the photolysis and hydrolysis studies. The correction procedures take into account the interference caused by minor or unknown products and have shown considerable improvement in the assay data in terms of the molar balance. The treatment of the corrected data has led to more accurate kinetic results in degradation studies.     

Ophioderma peruana,a new species of brittlestar (Echinodermata,Ophiuroidea, Ophiodermatidae) from?the Peruvian coast

Ophioderma peruana sp. n. is a new species of Ophiodermatidae, extending the distribution of the genus Ophioderma to Lobos de Afuera Island, Peru, easily distinguishable from its congeners by its peculiarly fragmented dorsal arm plates. Dense granules, rounded or polygonal cover the disc, the radial shields may be naked or completely covered by granules. A good character for recognizing this species in the field is the dorsal side of the disc which is brown with disc granules lighter cream and brown, the arms are mottled with whitish spots and the ventral part of the disc on the interradial part is brown and the radial part bright yellow.     

The glyceraldehyde-3-phosphate dehydrogenase promoter of the food yeast Candida utilis strain NRRL Y-660 is functional in Agrobacterium tumefaciens

The glyceraldehyde-3-phosphate dehydrogenase promoter of the food yeast Candida utilis strain NRRL Y-660 was cloned to create a novel integrative vector for Agrobacterium tumefaciens-mediated transformation. The new binary vector harbors β-glucuronidase activity as reporter and kanamicin/geneticin resistance as selection marker. Recombinant clones of A. tumefaciens show kanamycin resistance and high β-glucuronidase activity under the control of the C. utilis promoter. This finding can be explained by the presence of a prokaryotic core in the yeast promoter, predicted by in silico analysis of the sequence. This is the first report about functionality of a yeast promoter in A. tumefaciens.     

Oxygen supply strongly influences metabolic fluxes,the production of poly(3-hydroxybutyrate) and alginate,and the degree of acetylation of alginate in Azotobacter vinelandii

The aim of this study was to evaluate carbon flux in Azotobacter vinelandii using metabolic flux analysis (MFA) under high and low aeration conditions to achieve an improved understanding of how these changes could be related to alginate acetylation and PHB production. Changes in oxygen availability had a considerable impact on the metabolic fluxes and were reflected in the growth rate, the specific glucose consumption rate, and the alginate and PHB yields. The main differences at the metabolic flux level were observed in three important pathways. The first important difference was consistent with respiratory protection; an increase in the flux generated through the tricarboxylic acid (TCA) cycle for cultures grown under high aeration conditions (up to 2.61 times higher) was observed. In the second important difference, the fluxes generated through pyruvate dehydrogenase, phosphoenol pyruvate carboxykinase and pyruvate kinase, all of which are involved in acetyl-CoA metabolism, increased by 10, 43.9 and 17.5%, respectively, in cultures grown under low aeration conditions compared with those grown under high aeration conditions. These changes were related to alginate acetylation, which was 2.6 times higher in the cultures with limited oxygen, and the changes were also related to a drastic increase in PHB production. Finally, the glyoxylate shunt was active under both of the conditions that were tested, and a 2.79-fold increase was observed in cultures that were grown under the low aeration condition.     

Evidence for Introduction Bottleneck and Extensive Inter-Gene Pool (Mesoamerica x Andes) Hybridization in the European Common Bean (Phaseolus vulgaris L.) Germplasm

Common bean diversity within and between Mesoamerican and Andean gene pools was compared in 89 landraces from America and 256 landraces from Europe, to elucidate the effects of bottleneck of introduction and selection for adaptation during the expansion of common bean (Phaseolus vulgaris L.) in Europe. Thirteen highly polymorphic nuclear microsatellite markers (nuSSRs) were used to complement chloroplast microsatellite (cpSSRs) and nuclear markers (phaseolin and Pv-shatterproof1) data from previous studies. To verify the extent of the introduction bottleneck, inter-gene pool hybrids were distinguished from “pure” accessions. Hybrids were identified on the basis of recombination of gene pool specific cpSSR, phaseolin and Pv-shatterproof1 markers with a Bayesian assignments based on nuSSRs, and with STRUCTURE admixture analysis. More hybrids were detected than previously, and their frequency was almost four times larger in Europe (40.2%) than in America (12.3%). The genetic bottleneck following the introduction into Europe was not evidenced in the analysis including all the accessions, but it was significant when estimated only with “pure” accessions, and five times larger for Mesoamerican than for Andean germplasm. The extensive inter-gene pool hybridization generated a large amount of genotypic diversity that mitigated the effects of the bottleneck that occurred when common bean was introduced in Europe. The implication for evolution and the advantages for common bean breeding are discussed.