Photosynthetic response to water stress and changes in metabolites in <Emphasis Type="Italic">Jasminum sambac</Emphasis>

Gas exchange, chlorophyll (Chl) fluorescence, and contents of some metabolites in two genotypes of jasmine (Jasminum sambac), single petal (SP) and double petal (DP) one, were analyzed during dehydration and re-hydration. Water stress significantly decreased net photosynthetic rate, stomatal conductance, and maximum photochemical efficiency (F_v/F_m) in both jasmine genotypes, but increased minimum fluorescence (F₀) only in DP-jasmine. Water stress also decreased starch content, while increased contents of total soluble sugars and proline in leaves of both genotypes. SP-jasmine demonstrated higher drought tolerance as evidenced by maintaining higher gas exchange and photochemical efficiency and lower alteration of metabolites than DP-jasmine. Recovery analysis revealed that drought-induced injury in photosynthetic machinery in jasmine plants was reversible. DP-jasmine exhibited a slow recovery of drought-induced impairment in photosynthetic activity and associated metabolites, suggesting that this genotype had lower capacity to adapt to water limited condition. Higher yield stability of SP-than that of DP-jasmine under rain-fed condition finally confirmed higher drought tolerance of SP-jasmine.     

Combination of Ascorbate and α-Tocopherol as a Preventive Therapy against Structural and Functional Defects of Erythrocytes in Visceral Leishmaniasis

The redox unbalance in erythrocytes has been found to contribute significantly in the development of anemia in visceral leishmaniasis (VL). The present study revealed enhanced production of reactive oxygen species (ROS) and gradual depletion of α-tocopherol and ascorbate in the erythrocytes of infected animals. The response of erythrocytes to chronic treatment with antioxidants was studied in hamsters during leishmanial infection. Treatment with a combination of α-tocopherol and ascorbate proved to be the most effective preventive for the proteolytic degradation of erythrocyte membrane. Erythrocytes from infected animals were thermally more sensitive compared to the control ones. Combination of both antioxidants was most successful in resisting heat induced structural defects in the cells. Cross-linking of membrane proteins subsequent to oxidative damage in the red cells was accompanied by the formation of high molecular weight protein band at the top of the resolving gel in the presence of the cross-linking agent dimethyladepimidate (DMA). Marked inhibition of cross-linking was observed with combination of both antioxidants. Treatment with α-tocopherol and ascorbate together could withstand osmotic lysis of erythrocytes in the infected animals very efficiently. Decreased hemoglobin (Hb) level was successfully replenished and was coupled with significant increase in the life span of red cells after treating the animals with both antioxidants. Results indicate better efficacy of the combination therapy with α-tocopherol and ascorbate in protecting the erythrocytes from structural and functional damages during leishmanial infection.     

Supplementation with vascular endothelial growth factor during in vitro maturation of porcine cumulus oocyte complexes and subsequent developmental competence after in vitro fertilization

The aim of the present study was to investigate whether the effects of vascular endothelial growth factor (VEGF) on porcine cumulus oocyte complexes (COCs) and subsequent blastocyst formation following in vitro fertilization are attributable to improved fertilization and cytoplasmic maturation. Porcine COCs were cultured for 42 h in TCM199 medium with 5 ng/mL human recombinant VEGF, and the resultant metaphase II oocytes were fertilized in vitro. COCs without VEGF supplementation served controls. Supplementation with VEGF during in vitro maturation (IVM) significantly (P < 0.05) improved the blastocyst formation rate and total cell number (46.7 ± 3.1% and 82.8 ± 6.7, respectively) compared with controls (32.5 ± 3.4% and 64.1 ± 5.6, respectively). On day 2, the percentage of four-cell stage embryos was significantly higher in the VEGF-matured group (49.1 ± 2.7%) than in the control (33.1 ± 5.8%), and the percentage of two-cell stage embryos was significantly higher in the control group (10.4 ± 1.4%) than in the VEGF-matured group (6.6 ± 0.9%). At 10 h after the onset of in vitro fertilization (IVF), oocytes with two pronuclei were considered as monospermically or normally fertilized, and oocytes with more than two pronuclei were considered as polyspermically fertilized. Monospermy was significantly higher in VEGF-matured oocytes (47.2 ± 4.3%) than in the control (20.0 ± 2.4%), and polyspermy and sperm penetration per oocyte were significantly higher in the control group (54.4 ± 3.8% and 2.3 ± 0.1, respectively) than in the VEGF-matured oocytes (43.9 ± 3.6% and 1.8 ± 0.1, respectively). Supplementation with VEGF during IVM significantly (P < 0.05) improved male pronuclear formation as compared with the control (91.1 ± 1.9 vs 74.4 ± 3.8%). Type III cortical granule distribution in oocytes was more common in VEGF-matured oocytes (78.0%) than in the control (52.1%). These results suggest that VEGF supplementation during IVM enhanced the developmental potential of porcine IVF embryos through higher male pronuclear formation and higher monospermic fertilization rates as a consequence of improved cytoplasmic maturation.     

Signature amino acids enable the archaeal L7Ae box C/D RNP core protein to recognize and bind the K-loop RNA motif

The archaeal L7Ae and eukaryotic 15.5kD protein homologs are members of the L7Ae/15.5kD protein family that characteristically recognize K-turn motifs found in both archaeal and eukaryotic RNAs. In Archaea, the L7Ae protein uniquely binds the K-loop motif found in box C/D and H/ACA sRNAs, whereas the eukaryotic 15.5kD homolog is unable to recognize this variant K-turn RNA. Comparative sequence and structural analyses, coupled with amino acid replacement experiments, have demonstrated that five amino acids enable the archaeal L7Ae core protein to recognize and bind the K-loop motif. These signature residues are highly conserved in the archaeal L7Ae and eukaryotic 15.5kD homologs, but differ between the two domains of life. Interestingly, loss of K-loop binding by archaeal L7Ae does not disrupt C′/D′ RNP formation or RNA-guided nucleotide modification. L7Ae is still incorporated into the C′/D′ RNP despite its inability to bind the K-loop, thus indicating the importance of protein–protein interactions for RNP assembly and function. Finally, these five signature amino acids are distinct for each of the L7Ae/L30 family members, suggesting an evolutionary continuum of these RNA-binding proteins for recognition of the various K-turn motifs contained in their cognate RNAs.     

Expression of gonococcal transferrin-binding protein 1 causes Escherichia coli to bind human transferrin.

The gene for gonococcal transferrin-binding protein 1 (TBP1) was cloned behind an inducible promoter in Escherichia coli. The resultant strain was capable of binding human transferrin with the same specificity as that of the gonococcus. E. coli expressing TBP1 did not internalize transferrin-bound iron or grow on transferrin as a sole iron source.     

Modelling and Characterization of Glial Fibrillary Acidic Protein

Glial Fibrillary Acidic Protein (GFAP) is an intermediate-filament (IF) protein that maintains the astrocytes of the Central Nervous System in Human. This is differentially expressed during serological studies in inflamed condition such as Rheumatoid Arthritis (RA). Therefore, it is of interest to glean molecular insight using a model of GFAP (49.88 kDa) due to its crystallographic nonavailability. The present study has been taken into consideration to construct computational protein model using Modeller 9.11. The structural relevance of the protein was verified using Gromacs 4.5 followed by validation through PROCHECK, Verify 3D, WHAT-IF, ERRAT and PROVE for reliability. The constructed three dimensional (3D) model of GFAP protein had been scrutinized to reveal the associated functions by identifying ligand binding sites and active sites. Molecular level interaction study revealed five possible surface cavities as active sites. The model finds application in further computational analysis towards drug discovery in order to minimize the effect of inflammation.     

The type III secretion system needle,tip, and translocon

Many Gram‐negative bacteria pathogenic to plants and animals deploy the type III secretion system (T3SS) to inject virulence factors into their hosts. All bacteria that rely on the T3SS to cause infectious diseases in humans have developed antibiotic resistance. The T3SS is an attractive target for developing new antibiotics because it is essential in virulence, and part of its structural component is exposed on the bacterial surface. The structural component of the T3SS is the needle apparatus, which is assembled from over 20 different proteins and consists of a base, an extracellular needle, a tip, and a translocon. This review summarizes the current knowledge on the structure and assembly of the needle, tip, and translocon.     

Impact of hyperglycemia on the expression of GLUT1 during oral carcinogenesis in rats

Molecular Biology Reports - On the background of the epidemiological link between diabetes and oral cancer, the present study aimed to analyze the potential involvement of selected glucose...