scholarly journals IDENTIFICATION AND PARTIAL CHARACTERIZATION OF CRUDE EXTRACELLULAR ENZYMES FROM BACTERIA ISOLATED FROM SHRIMP WASTE PROCESSING

2013 ◽  
Vol 7 (1) ◽  
pp. 11 ◽  
Author(s):  
Ekowati Chasanah ◽  
Mahrus Ali ◽  
Miftahul Ilmi
Keyword(s):  
Hydrolytic Enzyme ◽  
Value Added ◽  
Biologically Active ◽  
Future Application ◽  
Chloride Salt ◽  
Shrimp Waste ◽  
Chitinolytic Enzyme ◽  
Degrading Enzymes ◽  
Chitosan Oligomer

Attention on chitin degrading enzymes has been growing since their ability to reduce the waste of shrimp/other crustaceans processing industries and converting them into value added products such as biologically active chitin and chitosan oligomer. Previous experiment found that KLU 11.16 isolate was one of the potential bacteria isolated from shrimp waste producing chitinolytic enzymes including chitosanases. A study on the identification of KLU 11.16 extracellularcrude enzyme was carried out by cultivating the bacteria on chitin medium. Due to the wide application of chitosanase, the characterization of the crude chitosanase was carried out after an identification of the enzymes secreted. Based on assessment using zymogram technique, this bacteria secreted a mixed extracellular chitinolytic enzyme and other hydrolytic enzyme. The crudechitinolytic enzyme degraded 85% deacetylated (DA) better than 100% DA chitosan, and slightly degraded glycol chitin, indicating that KLU 11.16 secreted chitosanases and chitinases enzyme. In addition to the chitinolytic enzyme, the bacteria also secreted protein and carbohydrate degrading enzymes when running at SDS-PAGE enriched with casein, soluble starch and CMC substrates.Crude chitosanases enzyme was performed well at pH 6 and temperature of 300C, and the activity can be increased by addition of 1 mM Fe 2+ in form of chloride salt. Addition of detergent, i.e1mM of Triton X-100 and SDS slightly decreased the activity. Future application of the crude chitosanase from KLU 11.16 was on producing chitosan derivative such as chitosan oligomer using substrateof 85% DA chitosan, which is more digestable by other enzymes secreted by KLU 11.16

Characterization of photosystem II with the atomic-force microscope

1992 ◽  
Vol 50 (2) ◽  
pp. 1146-1147
Author(s):  
Kathleen M. Marr ◽  
Mary K. Lyon
Keyword(s):  
Photosystem Ii ◽  
Atomic Force Microscope ◽  
Three Dimensional ◽  
Biologically Active ◽  
Atomic Force ◽  
Freeze Etching ◽  
Image Averaging ◽  
Oxygen Evolving ◽  
Averaging Techniques

Photosystem II (PSII) is different from all other reaction centers in that it splits water to evolve oxygen and hydrogen ions. This unique ability to evolve oxygen is partly due to three oxygen evolving polypeptides (OEPs) associated with the PSII complex. Freeze etching on grana derived insideout membranes revealed that the OEPs contribute to the observed tetrameric nature of the PSIl particle; when the OEPs are removed, a distinct dimer emerges. Thus, the surface of the PSII complex changes dramatically upon removal of these polypeptides. The atomic force microscope (AFM) is ideal for examining surface topography. The instrument provides a topographical view of individual PSII complexes, giving relatively high resolution three-dimensional information without image averaging techniques. In addition, the use of a fluid cell allows a biologically active sample to be maintained under fully hydrated and physiologically buffered conditions. The OEPs associated with PSII may be sequentially removed, thereby changing the surface of the complex by one polypeptide at a time.

Characterization of Biologically Active Substances from Calendula officinalis

2018 ◽  
Vol 18 (14) ◽  
pp. 1167-1174 ◽  
Author(s):  
Petra Lovecka ◽  
Jan Lipov ◽  
Kamila Thumova ◽  
Anna Macurkova
Keyword(s):  
Biologically Active Substances ◽  
Biologically Active ◽  
Calendula Officinalis ◽  
Active Substances

scholarly journals Unravelling the Skin Secretion Peptides of the Gliding Leaf Frog, Agalychnis spurrelli (Hylidae)

Biomolecules ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 667 ◽  
Author(s):  
Carolina Proaño-Bolaños ◽  
Ailín Blasco-Zúñiga ◽  
José Rafael Almeida ◽  
Lei Wang ◽  
Miguel Angel Llumiquinga ◽  
...  
Keyword(s):  
Inhibitory Concentration ◽  
Structural Diversity ◽  
Biologically Active ◽  
Biological Characterization ◽  
Skin Secretion ◽  
Peptide Profile ◽  
Active Chemical ◽  
Molecular Masses ◽  
Skin Secretions

Frog skin secretions contain medically-valuable molecules, which are useful for the discovery of new biopharmaceuticals. The peptide profile of the skin secretion of Agalychnis spurrelli has not been investigated; therefore, the structural and biological characterization of its compounds signify an inestimable opportunity to acquire new biologically-active chemical scaffolds. In this work, skin secretion from this amphibian was analysed by molecular cloning and tandem mass spectrometry. Although the extent of this work was not exhaustive, eleven skin secretion peptides belonging to five peptide families were identified. Among these, we report the occurrence of two phyllokinins, and one medusin-SP which were previously reported in other related species. In addition, eight novel peptides were identified, including four dermaseptins, DRS-SP2 to DRS-SP5, one phylloseptin-SP1, and three orphan peptides. Phylloseptin-SP1 and dermaseptins-SP2 were identified in HPLC fractions based on their molecular masses determined by MALDI-TOF MS. Among the antimicrobial peptides, dermaseptin-SP2 was the most potent, inhibiting Escherichia coli, Staphylococcus aureus, and ORSA with a minimum inhibitory concentration (MIC) of 2.68 μM, and Candida albicans with an MIC of 10.71 μM, without haemolytic effects. The peptides described in this study represent but a superficial glance at the considerable structural diversity of bioactive peptides produced in the skin secretion of A. spurrelli.

STUDIES ON ACTH-BINDING ANTIBODIES: CHARACTERIZATION OF IMMUNOLOGICAL SPECIFICITIES

1969 ◽  
Vol 62 (3) ◽  
pp. 521-536 ◽  
Author(s):  
M. L. Aubert ◽  
J.-P. Felber
Keyword(s):  
Binding Sites ◽  
Competitive Inhibition ◽  
Biologically Active ◽  
Active Part ◽  
Terminal Portion ◽  
Plasma Acth ◽  
Acth Fragments ◽  
Selection Of

ABSTRACT In investigations on the production and the specificity of anti-ACTH antibodies used for radioimmunoassay, differences have been observed between the various antibodies obtained. It was shown by means of competitive inhibition with different ACTH fragments that the binding of the ACTH molecule to its antibody can occur at different sites along the ACTH peptide. By varying the concentrations of the fragments and the conditions of the assays, it was possible to study the properties of each antibody. Thus antibodies which bind the N-terminal portion, or which exclusively bind the biologically active part of the ACTH chain (1–20), are the most suitable for radioimmunoassay. It was found, however, that the production of antiserum was generally more frequent when binding occurred to the C-terminal portion of the ACTH peptide. Should the presence of such fragments in plasma be confirmed, then the use of these antisera could lead to erroneous measurement of biologically inactive ACTH fragments. Thus, this study reveals that a selection of the antibody for specificity might be necessary for its application to the radioimmunoassay of plasma ACTH, and that this selection could be performed with the use of ACTH fragments. An approach to the problem of binding sites between antigen and antibody has been described and the possibility of introducing a radioimmunoassay for plasma ACTH fragments discussed.

Evaluation and Characterization of TiAlZr Alloys Coated with Apatite or Albumin-Apatite Composite

2007 ◽  
Vol 361-363 ◽  
pp. 733-736 ◽  
Author(s):  
D. Ionita ◽  
E. Aldea ◽  
G. Stanciu ◽  
Ioana Demetrescu
Keyword(s):  
Surface Characteristics ◽  
Biologically Active

The aim of this paper was to find and establish the contact: biomaterial implant (TiAlZr) - coated with biologically active molecules; and the correlation between surface characteristics and their efficiency.

Purification and characterization of an exochitinase from Bacillus thuringiensis subsp. aizawai and its action against phytopathogenic fungi

2006 ◽  
Vol 52 (7) ◽  
pp. 651-657 ◽  
Author(s):  
Luis Morales de la Vega ◽  
J Eleazar Barboza-Corona ◽  
Maria G Aguilar-Uscanga ◽  
Mario Ramírez-Lepe
Keyword(s):  
Bacillus Thuringiensis ◽  
Sodium Dodecyl ◽  
Sclerotium Rolfsii ◽  
Phytopathogenic Fungi ◽  
Purification And Characterization ◽  
Chitinolytic Enzyme ◽  
Bacillus Thuringiensis Subsp ◽  
Sds Page ◽  
Fusarium Sp

A chitinolytic enzyme from Bacillus thuringiensis subsp. aizawai has been purified and its molecular mass was estimated ca. 66 kDa by sodium dodecyl sulfate – polyacryamide gel electrophoresis (SDS–PAGE). The enzyme was able to hydrolyze chitin to chitobiosides but not carboxymethylcellulose, cellulose, pullulan, and laminarin. Optimal pH and temperature were detected at 6 and 50 °C, respectively. Stability, in the absence of substrate, was observed at temperatures less than 60 °C and pH between 5 and 8. Enzyme activity was significantly inhibited by K+ and EDTA and completely inhibited by Hg2+. Purified chitinase showed lytic activity against cell walls from six phytopathogenic fungi and inhibited the mycelial growth of both Fusarium sp. and Sclerotium rolfsii. The biocontrol efficacy of the enzyme was tested in the protection of bean seeds infested with six phytopathogenic fungi.Key words: chitinase, Bacillus thuringiensis, purification, phytopathogenic fungi.

Construction and Characterization of Retroviral Vectors Expressing Biologically Active Human Interleukin-12

1994 ◽  
Vol 5 (12) ◽  
pp. 1493-1506 ◽  
Author(s):  
Laurence Zitvogel ◽  
Hideaki Tahara ◽  
Quan Cai ◽  
Walter J. Storkus ◽  
Gunhild Muller ◽  
...  
Keyword(s):  
Retroviral Vectors ◽  
Biologically Active ◽  
Interleukin 12
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