• Title/Summary/Keyword: Biology I

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Diversity and Polymorphism in AHL-Lactonase Gene (aiiA) of Bacillus

  • Huma, Nusrat;Shankar, Pratap;Kushwah, Jyoti;Bhushan, Ashish;Joshi, Jayadev;Mukherjee, Tanmoy;Raju, Sajan C.;Purohit, Hemant J.;Kalia, Vipin Chandra
    • Journal of Microbiology and Biotechnology
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    • v.21 no.10
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    • pp.1001-1011
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    • 2011

  • To explore bacterial diversity for elucidating genetic variability in acylhomoserine lactone (AHL) lactonase structure, we screened 800 bacterial strains. It revealed the presence of a quorum quenching (QQ) AHL-lactonase gene (aiiA) in 42 strains. These 42 strains were identified using rrs (16S rDNA) sequencing as Bacillus strains, predominantly B. cereus. An in silico restriction endonuclease (RE) digestion of 22 AHL lactonase gene (aiiA) sequences (from NCBI database) belonging to 9 different genera, along with 42 aiiA gene sequences from different Bacillus spp. (isolated here) with 14 type II REs, revealed distinct patterns of fragments (nucleotide length and order) with four REs; AluI, DpnII, RsaI, and Tru9I. Our study reflects on the biodiversity of aiiA among Bacillus species. Bacillus sp. strain MBG11 with polymorphism (115Alanine > Valine) may confer increased stability to AHL lactonase, and can be a potential candidate for heterologous expression and mass production. Microbes with ability to produce AHL-lactonases degrade quorum sensing signals such as AHL by opening of the lactone ring. The naturally occurring diversity of QQ molecules provides opportunities to use them for preventing bacterial infections, spoilage of food, and bioremediation.

  • https://doi.org/10.4014/jmb.1105.05056 인용 PDF KSCI

Detection of Serum Anti-Extracellular Protein Kinase a Autoantibodies as a Potential Tumor Marker

  • Lee, Seung-Ho;Kim, Ki-Nam;Seo, Sang-Hui;Sohn, Sung-Hwa;Kim, Yu-Ri;Kim, Hye-Won;Choi, Chul-Won;Kim, Jun-Suk;Kim, Meyoung-Kon
    • Molecular & Cellular Toxicology
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    • v.2 no.1
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    • pp.67-73
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    • 2006

  • In previous studies, it has been discovered that cancer cells not only overexpress regulatory subunit I (Rl)/protein kinase type I (PKA-I) but also secrete outside the cell an extracellular form of PKA (ECPKA) and that the ECPKA secretion detected in patients' serum is obviously greater than that found in non-cancer patients or healthy subjects. We now found that ECPKA elicits the formation of serum autoantibodies that can serve as a cancer diagnostic and prognostic marker. To measure the presence of anti-ECPKA autoantibody in the human sera, basic methodology for ECPKA assay was established an enzyme-linked immunosorbent assay (ELISA). We obtained serum samples from 199 patients with different types of cancer, and also obtained 31 serum samples to compare with ECPKA concentrations from non-cancer patients and 119 normal volunteers. Compared with normal or non-cancer patient sera, we found that the frequency of anti-ECPKA autoantibody was significantly higher in cancer patients (88%) than in those without cancer (17%). Furthermore the presence of anti-ECPKA autoantibodies in the serum of cancer patients was highly correlated with the site of metastasis. The immunoassay developed for anti-ECPKA antibodies is highly sensitive and specific. Therefore, this discovery of an autoantibody-based cancer diagnostic may have serious clinical application and may become an important advance over current technology.

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Biological and Ecological Considerations of the Freshwater Amphipod, Diporeia spp.

  • Song, Ki-Hoon
    • Korean Journal of Environmental Biology
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    • v.21 no.4
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    • pp.328-336
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    • 2003

  • Biological and ecological characteristics of Diporeia spp. are described including size, growth, life cycle, energy storage, temperature effect, bioturbation, feeding depth and sediment ingestion of Diporeia. Bioaccumulation and toxicity of organic contaminants and trace metals were reviewed in addition to an examination of the relationships among various condition indexes (i.e. wet weight, dry weight and body length) of Diporeia.

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