The Critical Role of N- and C-Terminal Contact in Protein Stability and Folding of a Family 10 Xylanase under Extreme Conditions

Stabilization strategies adopted by proteins under extreme conditions are very complex and involve various kinds of interactions. Recent studies have shown that a large proportion of proteins have their N- and C-terminal elements in close contact and suggested they play a role in protein folding and stability. However, the biological significance of this contact remains elusive.In the present study, we investigate the role of N- and C-terminal residue interaction using a family 10 xylanase (BSX) with a TIM-barrel structure that shows stability under high temperature, alkali pH, and protease and SDS treatment. Based on crystal structure, an aromatic cluster was identified that involves Phe4, Trp6 and Tyr343 holding the N- and C-terminus together; this is a unique and important feature of this protein that might be crucial for folding and stability under poly-extreme conditions. folding and activity. Alanine substitution with Phe4, Trp6 and Tyr343 drastically decreased stability under all parameters studied. Importantly, substitution of Phe4 with Trp increased stability in SDS treatment. Mass spectrometry results of limited proteolysis further demonstrated that the Arg344 residue is highly susceptible to trypsin digestion in sensitive mutants such as ΔF4, W6A and Y343A, suggesting again that disruption of the Phe4-Trp6-Tyr343 (F-W-Y) cluster destabilizes the N- and C-terminal interaction. Our results underscore the importance of N- and C-terminal contact through aromatic interactions in protein folding and stability under extreme conditions, and these results may be useful to improve the stability of other proteins under suboptimal conditions

Outcome Prediction in Pneumonia Induced ALI/ARDS by Clinical Features and Peptide Patterns of BALF Determined by Mass Spectrometry

BACKGROUND: Peptide patterns of bronchoalveolar lavage fluid (BALF) were assumed to reflect the complex pathology of acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) better than clinical and inflammatory parameters and may be superior for outcome prediction. METHODOLOGY/PRINCIPAL FINDINGS: A training group of patients suffering from ALI/ARDS was compiled from equal numbers of survivors and nonsurvivors. Clinical history, ventilation parameters, Murray's lung injury severity score (Murray's LISS) and interleukins in BALF were gathered. In addition, samples of bronchoalveolar lavage fluid were analyzed by means of hydrophobic chromatography and MALDI-ToF mass spectrometry (MALDI-ToF MS). Receiver operating characteristic (ROC) analysis for each clinical and cytokine parameter revealed interleukin-6>interleukin-8>diabetes mellitus>Murray's LISS as the best outcome predictors. Outcome predicted on the basis of BALF levels of interleukin-6 resulted in 79.4% accuracy, 82.7% sensitivity and 76.1% specificity (area under the ROC curve, AUC, 0.853). Both clinical parameters and cytokines as well as peptide patterns determined by MALDI-ToF MS were analyzed by classification and regression tree (CART) analysis and support vector machine (SVM) algorithms. CART analysis including Murray's LISS, interleukin-6 and interleukin-8 in combination was correct in 78.0%. MALDI-ToF MS of BALF peptides did not reveal a single identifiable biomarker for ARDS. However, classification of patients was successfully achieved based on the entire peptide pattern analyzed using SVM. This method resulted in 90% accuracy, 93.3% sensitivity and 86.7% specificity following a 10-fold cross validation (AUC = 0.953). Subsequent validation of the optimized SVM algorithm with a test group of patients with unknown prognosis yielded 87.5% accuracy, 83.3% sensitivity and 90.0% specificity. CONCLUSIONS/SIGNIFICANCE: MALDI-ToF MS peptide patterns of BALF, evaluated by appropriate mathematical methods can be of value in predicting outcome in pneumonia induced ALI/ARDS

Proteomics as the tool to search for lung disease markers in bronchoalveolar lavage

Most lung disorders are known to be associated to considerable modifications of surfactant composition. Numerous of these abnormalities have been exploited in the past to diagnose lung diseases, allowing proper treatment and follow-up. Diagnosis was then based on phospholipid content, surface tension and cytological features of the epithelial lining fluid (ELF), sampled by bronchoalveolar lavage (BAL) during fiberoscopic bronchoscopy. Today, it appears that the protein content of ELF displays a remarkably high complexity, not only due to the wide variety of the proteins it contains but also because of the great diversity of their cellular origins. The significance of the use of proteome analysis of BAL fluid for the search for new lung disease marker proteins and for their simultaneous display and analysis in patients suffering from lung disorders has been examined

Functional and Psychological Characteristics of Belgian Men with Premature Ejaculation and Their Partners

Physiological, behavioral, cognitive, and emotional factors are generally acknowledged to play a role in premature ejaculation (PE). However, the nature and the extent of their etiological impact remain largely imprecise. The present study examined functional and psychometric dynamics at work in a PE population. A total of 461 men with PE and 80 partners completed an online questionnaire. The main outcome measures were self-reported ejaculatory latency time, the feeling of control upon ejaculation, sexual satisfaction, distress related to PE, trait anxiety (STAI-B), sexual cognitions (SIQ), social anxiety (LSAS and SISST), and personality traits (TCI-R). In our sample, the median latency time to ejaculation was between 1 and 2 minutes. Sexual satisfaction and distress correlated more strongly with the feeling of control than with the self-reported latency time. Men experienced more distress and dissatisfaction related to PE than did their partners while overestimating their partners’ distress and dissatisfaction. PE participants’ scores differed significantly, albeit slightly, from STAI-B, SIQ, LSAS, and SISST norms. The differences were negligible on TCI-R. Some differences became stronger when subtypes were considered. Participants combining generalized and lifelong PE with self-reported latency times of < 30 sec reported lower sexual satisfaction and control, higher distress, higher social anxiety, and harm avoidance (TCI-R/HA) scores. By contrast, the situational subtype of PE was found to be characterized by a higher level of satisfaction, a greater feeling of control, less distress, and higher trait anxiety scores. However, the trends remained statistically discrete.BibliothE

Seagrass Community of The Coastal In Southern Of Bangka Island, North Minahasa Regancy, North Sulawesi Province

Purpose of this research is to know the community of seagrass, and physical-chemical parameters in the South Bangka island, North Minahasa Regancy, North Sulawesi Province. Data retrieval by the random sampling of systematic method on three lines transect with 50 m long, and 30 quadrants. Data taken in each quadrant is number of species and number of individuals of each species. Results of the measurement of physical and chemical parameters of static waters associated with the feasibility of life for water organisms in it, generally in good condition. Ten species of seagrass have been found in the southern part of the island of Bangka. Four species are always found in any transek i.e Syringodium isoetifolium, Cymodocea rotundata, Enhallus acaroides, and Halophylla ovalis. The highest found in seagrass cover transek 1 i.e. 67.00% while the lowest in transek 3 i.e. 46.30%.  Seagrass cover Enhallus acaroides in Bangka island very prominent compared to other species. Based on the current index value is important, Syringodium isoetifolium have a high importance value index only in the transek 3 which means this type of seagrass seagrass types affect other takes part in community level.  Ecological index results suggest that the ecosystem of seagrass in Bangka island in the southern part of the State is stable.Keywords: Seagrass, Bangka Island, importance value index (INP).   AbstrakTujuan penelitian ini untuk mengetahui komunitas lamun, dan parameter fisik-kimia di bagian Selatan Pulau Bangka; Kabupaten Minahasa Utara, Provinsi Sulawesi Utara.  Pengambilan data dengan metode sampling acak sistimatis; pada tiga transek yang diletakkan tegak lurus garis, sepanjang 50 m.  Jumlah kuadran yang digunakan sebanyak 30.  Data yang diambil dalam setiap kuadran dihitung jumlah jenis dan jumlah individu setiap jenis. Hasil pengukuran parameter fisik statis dan kimia perairan dihubungkan dengan kelayakan hidup bagi organisme air yang ada di dalamnya, umumnya dalam kondisi baik.  Telah ditemukan sepuluh spesies lamun di Pulau Bangka bagian selatan.  Empat spesies selalu dijumpai di setiap transek yaitu Cymodocea rotundata, Syringodium isoetifolium, Enhallus acoroides, dan Halophylla ovalis. Tutupan lamun tertinggi ditemukan di transek 1 yaitu 67,00 % sedangkan yang terendah di transek 3 yaitu 46,30 %.    Tutupan lamun Enhallus acaroides di Pulau Bangka sangat menonjol dibandingkan dengan jenis lainnya.  Berdasarkan nilai indeks nilai penting; jenis Syringodium isoetifolium memiliki indeks nilai penting yang tinggi hanya di transek 3 yang berarti jenis lamun ini turut mempengaruhi jenis lamun lainnya dalam tingkat komunitas. Hasil indeks ekologi  menunjukkan bahwa ekosistem lamun di Pulau Bangka bagian Selatan dalam keadaan stabil.Kata kunci: Lamun, Pulau Bangka, Indeks Nilai Penting (INP)</jats:p

Key role of Ser562/661 in Snf1-dependent regulation of Cat8p in Saccharomyces cerevisiae and Kluyveromyces lactis.

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