Distribusi dan Kelimpahan Gastropoda pada Hutan Mangrove Teluk Awur Jepara

Teluk Awur Jepara merupakan pesisir yang memiliki hutan mangrove yang dijadikan permodelan untuk program rehabilitasi mangrove. Untuk pengelolaan kawasan hutan mangrove secara terpadu perlu diketahui keberadaan biota yang ada di dalamnya. Gastropoda merupakan penghuni tetap hutan mangrove dengan informasi yang masih kurang sehingga perlu dilakukan penelitian tentang kelimpahan dan distribusi gastropoda di dalam hutan mangrove tersebut. Pengambilan sampel menggunakan 3 buah Line Transect sepanjang 100 m dengan jarak 30 m. Line ditempatkan tegak lurus dengan garis pantai. Pengamatan vegetasi mangrove menggunakan metode transek yang berukuran 10x10 m2 yaitu untuk pengamatan tingkat pohon, 5x5 m2 sebanyak dua buah dan 1x1 m2 sebanyak lima buah untuk pengamatan vegetasi mangrove tingkat pancang dan semai. Pengambilan data sampel gastropoda menggunakan kuadran 1x1 m2 sebanyak lima buah yang ditempatkan secara acak pada kuadran 10x10m2. Jenis gastropoda yang ditemukan di hutan mangrove Teluk Awur Jepara didapat 16 jenis yaitu Cerithidea cingulata, Cerithidea cingulata cingulata, Cerithidea quadrata, Cerithidea obtusa, Litorina carinifera, Littorina angulifera, Littorina scabra, Casidula nucleus, Casidula aurisfelis, Casidula multiflicata, Melampus nuxcastaneus, Melampus coffeus, Telescopium telescopium, Sphaerassiminea miniata, Neritina violacea dan Pythia plicata. Vegetasi mangrove yang paling mendominasi adalah Rhizophora mucronata baik pada tingkat pohon, pancang, dan semai. Jenis gastropoda yang paling melimpah dan mendominasi adalah Cerithidea cingulata dan Casidula nucleus. Cerithidea cingulata lebih mendominasi pada daerah mangrove terbuka sedangkan Casidula nucleus mendominasi pada daerah mangrove tertutup yaitu pada daerah mangrove yang lebih rapat. Distribusi gastropoda pada umumnya mengelompok. Keberadaan gastropoda pada hutan mangrove dipengaruhi oleh vegetasi hutan mangrove

Xanthene Food Dye, as a Modulator of Alzheimer's Disease Amyloid-beta Peptide Aggregation and the Associated Impaired Neuronal Cell Function

Alzheimer's disease (AD) is the most common form of dementia. AD is a degenerative brain disorder that causes problems with memory, thinking and behavior. It has been suggested that aggregation of amyloid-beta peptide (Aβ) is closely linked to the development of AD pathology. In the search for safe, effective modulators, we evaluated the modulating capabilities of erythrosine B (ER), a Food and Drug Administration (FDA)-approved red food dye, on Aβ aggregation and Aβ-associated impaired neuronal cell function.In order to evaluate the modulating ability of ER on Aβ aggregation, we employed transmission electron microscopy (TEM), thioflavin T (ThT) fluorescence assay, and immunoassays using Aβ-specific antibodies. TEM images and ThT fluorescence of Aβ samples indicate that protofibrils are predominantly generated and persist for at least 3 days. The average length of the ER-induced protofibrils is inversely proportional to the concentration of ER above the stoichiometric concentration of Aβ monomers. Immunoassay results using Aβ-specific antibodies suggest that ER binds to the N-terminus of Aβ and inhibits amyloid fibril formation. In order to evaluate Aβ-associated toxicity we determined the reducing activity of SH-SY5Y neuroblastoma cells treated with Aβ aggregates formed in the absence or in the presence of ER. As the concentration of ER increased above the stoichiometric concentration of Aβ, cellular reducing activity increased and Aβ-associated reducing activity loss was negligible at 500 µM ER.Our findings show that ER is a novel modulator of Aβ aggregation and reduces Aβ-associated impaired cell function. Our findings also suggest that xanthene dye can be a new type of small molecule modulator of Aβ aggregation. With demonstrated safety profiles and blood-brain permeability, ER represents a particularly attractive aggregation modulator for amyloidogenic proteins associated with neurodegenerative diseases

Site-Specific Bioconjugation of a Murine Dihydrofolate Reductase Enzyme by Copper(I)-Catalyzed Azide-Alkyne Cycloaddition with Retained Activity

Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC) is an efficient reaction linking an azido and an alkynyl group in the presence of copper catalyst. Incorporation of a non-natural amino acid (NAA) containing either an azido or an alkynyl group into a protein allows site-specific bioconjugation in mild conditions via CuAAC. Despite its great potential, bioconjugation of an enzyme has been hampered by several issues including low yield, poor solubility of a ligand, and protein structural/functional perturbation by CuAAC components. In the present study, we incorporated an alkyne-bearing NAA into an enzyme, murine dihydrofolate reductase (mDHFR), in high cell density cultivation of Escherichia coli, and performed CuAAC conjugation with fluorescent azide dyes to evaluate enzyme compatibility of various CuAAC conditions comprising combination of commercially available Cu(I)-chelating ligands and reductants. The condensed culture improves the protein yield 19-fold based on the same amount of non-natural amino acid, and the enzyme incubation under the optimized reaction condition did not lead to any activity loss but allowed a fast and high-yield bioconjugation. Using the established conditions, a biotin-azide spacer was efficiently conjugated to mDHFR with retained activity leading to the site-specific immobilization of the biotin-conjugated mDHFR on a streptavidin-coated plate. These results demonstrate that the combination of reactive non-natural amino acid incorporation and the optimized CuAAC can be used to bioconjugate enzymes with retained enzymatic activityope

Designer Gene Delivery Vectors: Molecular Engineering and Evolution of Adeno-Associated Viral Vectors for Enhanced Gene Transfer

Gene delivery vectors based on adeno-associated virus (AAV) are highly promising due to several desirable features of this parent virus, including a lack of pathogenicity, efficient infection of dividing and non-dividing cells, and sustained maintenance of the viral genome. However, several problems should be addressed to enhance the utility of AAV vectors, particularly those based on AAV2, the best characterized AAV serotype. First, altering viral tropism would be advantageous for broadening its utility in various tissue or cell types. In response to this need, vector pseudotyping, mosaic capsids, and targeting ligand insertion into the capsid have shown promise for altering AAV specificity. In addition, library selection and directed evolution have recently emerged as promising approaches to modulate AAV tropism despite limited knowledge of viral structure–function relationships. Second, pre-existing immunity to AAV must be addressed for successful clinical application of AAV vectors. “Shielding” polymers, site-directed mutagenesis, and alternative AAV serotypes have shown success in avoiding immune neutralization. Furthermore, directed evolution of the AAV capsid is a high throughput approach that has yielded vectors with substantial resistance to neutralizing antibodies. Molecular engineering and directed evolution of AAV vectors therefore offer promise for generating ‘designer’ gene delivery vectors with enhanced properties