Role of spermidine in the stabilization of the apoprotein of the light-harvesting chlorophyll a/b-protein complex of photosystem II during leaf senescence process

Barley leaf discs maintained in dark accumulated a massive amount of putrescine (Put), lost chlorophyll and senescenced rapidly. At the same time RNase activity increased significantly. Exogenous spermidine (Spd) inhibited RNase activity, the loss of chlorophyll and degradation of the proteins from thylakoid membranes. Using SDS-PAGE and immunoblot analysis it was shown that spermidine was effective in the retardation of the loss of LHCPII observed in water-treated detached leaves. Analysis of PSII particles isolated from leaf fragments floated in water in the dark revealed the presence of Put, Spd and Spm. In spermidine treated leaves the level of this polyamine in photosystem II was above 5-fold higher than in control. The experimental findings obtained in this study provide evidence that applied spermidine interacts directly with thylakoid membranes so that they become more stable to degradation during senescence.     

Biochemical characterization and structural insight into aliphatic β‐amino acid adenylation enzymes IdnL1 and CmiS6

Macrolactam antibiotics such as incednine and cremimycin possess an aliphatic β‐amino acid as a starter unit of their polyketide chain. In the biosynthesis of incednine and cremimycin, unique stand‐alone adenylation enzymes IdnL1 and CmiS6 select and activate the proper aliphatic β‐amino acid as a starter unit. In this study, we describe the enzymatic characterization and the structural basis of substrate specificity of IdnL1 and CmiS6. Functional analysis revealed that IdnL1 and CmiS6 recognize 3‐aminobutanoic acid and 3‐aminononanoic acid, respectively. We solved the X‐ray crystal structures of IdnL1 and CmiS6 to understand the recognition mechanism of these aliphatic β‐amino acids. These structures revealed that IdnL1 and CmiS6 share a common recognition motif that interacts with the β‐amino group of the substrates. However, the hydrophobic side‐chains of the substrates are accommodated differently in the two enzymes. IdnL1 has a bulky Leu220 located close to the terminal methyl group of 3‐aminobutanoate of the trapped acyl‐adenylate intermediate to construct a shallow substrate‐binding pocket. In contrast, CmiS6 possesses Gly220 at the corresponding position to accommodate 3‐aminononanoic acid. This structural observation was supported by a mutational study. Thus, the size of amino acid residue at the 220 position is critical for the selection of an aliphatic β‐amino acid substrate in these adenylation enzymes. Proteins 2017; 85:1238–1247. © 2017 Wiley Periodicals, Inc.     

Fungi inhabiting knotwood of Pinus sylvestris infected by Porodaedalea pini

Abundance and diversity of fungi in naturally formed knots of Pinus sylvestris affected by Porodaedalea pini were investigated. Samples were taken from trees that were (i) affected, with internal heartwood decay and no conks, (ii) affected, with internal heartwood decay and conks and (iii) controls. The Illumina sequencing technology was used for amplification of DNA, sequencing and analysis. In total, 566,279 raw sequences were obtained from six samples. Sequences included 74% of culturable and 8.4% of non‐culturable fungi and 17.6% of organisms with no reference sequences in NCBI. Abundance of organisms in knotwood, measured as number of OTUs, ranged from 36,272 (29,506 for fungi) to 178,535 (177,484 for fungi) and differed significantly between two trees in a stand and between stands. The highest and lowest average number of fungal OTUs occurred in infected trees with no conks and in trees with conks, respectively. Number of taxa ranged from 171 to 415 and often differed significantly between two trees in one stand and between stands. Greatest diversity occurred in control trees. The number of fungal taxa shared by two trees in one stand was 67–152 and that shared by two stands was 51–141. The majority of fungi were Ascomycota. Those most common in pines affected by P. pini were Coniochaeta hoffmannii and C. fodinicola (19.65%–59.92%). Infundichalara microchona, Leotiomycetes spp. and Rhinocladiella atrovirens were also present. Another common species, Lecanora conizaeoides, occurred most often in control trees (0.30%–8.82%). Porodaedalea pini was detected only sporadically. Non‐culturable fungi were most frequent in the control trees. The greater average abundance and smaller average diversity of fungi in knots of trees infected by P. pini suggest that the pathogen successfully competes with some fungal species and does not inhibit the growth of survivors. Some fungi detected may contribute to production of natural biocides.     

Two‐dimensional fluorescence as soft sensor in the monitoring of biotransformation performed by yeast

Soft sensors are powerful tools for bioprocess monitoring due to their ability to perform online, noninvasive measurement, and possibility of detection of multiple components in cultivation media, which in turn can provide tools for the quantification of more than one metabolite/substrate/product in real time. In this work, soft sensor based on excitation‐emission fluorescence is for the first time applied for the monitoring of biotransformation production of 2‐phenylethanol (2‐PE) by yeast strains. Main process parameters—such as optical density, glucose, and 2‐PE concentrations—were determined with high accuracy and precision by fluorescence fingerprinting coupled with partial least squares regression. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 33:299–307, 2017     

Practical application of daughter yield deviations in dairy cattle breeding

Daughter yield deviations (DYDs) of bulls and yield deviations (YDs) of cows, besides estimated breeding values (EBVs), are standard measures of animals' genetic merits in routine genetic evaluations worldwide. In this contribution, we first point out differences and similarities between DYDs and EBVs calculated for milk, fat and protein yields. While the latter measure represents the additive polygenic value of an animal, the former consists of both the additive polygenic and residual components. Then, a summary of DYDs and YDs calculated for the Polish population of dairy cattle is presented. The estimated correlations between DYDs and EBVs are generally high, but vary considerably depending on the minimum number of daughters used for calculation of DYDs and on the accuracy of calculated DYDs. Using DYDs estimated for each production year for 16 452 bulls, we demonstrate how to use DYDs for the validation of genetic trend estimated in the model used for genetic evaluation. Based on genotypic data of 252 bulls, we show that DYDs can be used for the estimation of candidate gene effects. For each of the yield traits, the within-bull genetic trend was relatively high, ranging between 1.39% of genetic standard deviation per production year for milk and 7.67% of genetic standard deviation per production year for fat, both in the 2nd lactation. Out of 8 polymorphisms tested, 5 showed a significant correlation with DYD, with the highest effect attributed to the polymorphism within the leptin receptor gene, whose additive effect was estimated as 247.33 kg of milk at 2nd parity.     

Apigenin inhibits growth and motility but increases gap junctional coupling intensity in rat prostate carcinoma (MAT-LyLu) cell populations

Apigenin (4',5,7,-trihydroxyflavone) is a flavonoid abundant in the common fruits, herbs and vegetables constituting the bulk of the human diet. This study was aimed at quantifying the effects of apigenin on the basic cellular traits determining cancer development, i.e. cell proliferation, gap junctional coupling, and motility, using the Dunning rat prostate MAT-LyLu cell model. We demonstrated that apigenin considerably inhibits MAT-LyLu cell proliferation and significantly enhances the intensity of connexin43-mediated gap junctional coupling. This effect correlates with an increased abundance of Cx43-positive plaques at the cell-to-cell borders seen in apigenin-treated variants. Moreover, we observed an inhibitory effect of apigenin on the motility of MAT-LyLu cells. The basic parameters characterising MAT-LyLu cell motility, especially the rate of cell displacement, considerably decreased upon apigenin administration. This in vitro data indicates that apigenin may affect cancer development in general, and prostate carcinogenesis in particular, via its influence on cellular activities decisive for both cancer promotion and progression, including cell proliferation, gap junctional coupling and cell motility and invasiveness.     

131I-MIBG therapy in the treatment of pheochromocytoma in children--own experiences

Three cases of pheochromocytoma in children/adolescents or young adults treated by 131I-MIBG are presented in this study. In one patient 131I-MIBG was administrated after ineffective surgical treatment and chemotherapy of a benign retroperitoneal tumor, whereas in two other patients 131I-MIBG therapy was carried out because of malignant pheochromocytoma dissemination. In a child with retroperitoneal paraganglioma decrease of tumor size and its fibrosis after 131I-MIBG therapy allowed radical surgery and complete recovery. In two other cases partial remission was achieved. All patients showed a good subjective response with improvement of the general condition and better blood pressure control. In two children adverse reactions such as leucopenia, hypothyroidism or hypogonadism were observed. The presented data confirm effectiveness and acceptable tolerance of 131I-MIBG treatment in pheochromocytoma, what is very important in pediatric patients.     

The immunosuppressive activity and solution structures of ubiquitin fragments

Recently, ubiquitin was suggested as a promising anti‐inflammatory protein therapeutic. We found that a peptide fragment corresponding to the ubiquitin^50–59 sequence (LEDGRTLSDY) possessed the immunosuppressive activity comparable with that of ubiquitin. CD and NMR spectroscopies were used to determine the conformational preferences of LEDGRTLSDY in solution. The peptide mixture, obtained by pepsin digestion of ubiquitin, was even more potent than the intact protein. Although the peptide exhibited a well‐defined conformation in methanol, its structure was distinct from the corresponding 50–59 fragment in the native ubiquitin molecule. © 2009 Wiley Periodicals, Inc. Biopolymers 91: 423–431, 2009. This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com     

WAFL, a new protein involved in regulation of early endocytic transport at the intersection of actin and microtubule dynamics

We have previously identified a new gene with sequence homology to the WASP-family of actin regulators denoted WAFL (WASP and FKBP-like). Here we report a possible biological function for WAFL, by demonstrating an association to early endosomes via its central coiled-coil domain. Further we show by functional and structural studies that WAFL is associated with both microtubules and the actin filament system, the two means of transport of early endosomes. In addition, WAFL interacts with WASP-interacting protein (WIP) and actin, thus linking WAFL to actin dynamics. The use of RNAi depletion of WAFL shows that WAFL-deficient cells display delayed transport of endosomal cargo. Our findings are compatible with a model whereby WAFL is involved in the transport of early endosomes at the level of transition between microfilament-based and microtubule-based movement.     

Determination of the pattern of acetylation of chitosan samples: Comparison of evaluation methods and some validation parameters

Chitosan is a linear copolymer consisting of glucosamine and N-acetylglucosamine units. Its specific biological features make it a very attractive biomaterial for diverse applications in both pharmaceutics and medicine. The pattern of acetylation of chitosan samples (P_A) can strongly influence their biomedical activities. So far, three methods of determining the P_A value of chitosan samples, based on NMR spectroscopy, have been developed. Chitosans with a degree of acetylation (F_A) from 0.02 to 0.48 were used to compare these methods. The most suitable and specific method of P_A determination was ¹³C NMR based on the intensities of carbon C-5 signals. Some validation parameters—specificity, sensitivity, precision (repeatability and reproducibility)—were established. The intra- and inter-day precision of this method depended on the degree of acetylation of the chitosan samples. It was found to be specific, sensitive, repeatable and reproducible.