Effects of detergents on catalytic activity of human endometase/matrilysin 2, a putative cancer biomarker

Matrix metalloproteinases (MMPs) are a family of hydrolytic enzymes that play significant roles in development, morphogenesis, inflammation, and cancer invasion. Endometase (matrilysin 2 or MMP-26) is a putative early biomarker for human carcinomas. The effects of the ionic and nonionic detergents on catalytic activity of endometase were investigated. The hydrolytic activity of endometase was detergent concentration dependent, exhibiting a bell-shaped curve with its maximum activity near the critical micelle concentration (CMC) of nonionic detergents tested. The effect of Brij-35 on human gelatinase B (MMP-9), matrilysin (MMP-7), and membrane-type 1 MMP (MT1-MMP) was further explored. Their maximum catalysis was observed near the CMC of Brij-35 (∼ 90 μM). Their IC₅₀ values were above the CMC. The inhibition mechanism of MMP-7, MMP-9, and MT1-MMP by Brij-35 was a mixed type as determined by Dixon’s plot; however, the inhibition mechanism of endometase was noncompetitive with a K_i value of 240 μM. The catalytic activities of MMPs are influenced by detergents. Monomer of detergents may activate and stabilize MMPs to enhance catalysis, but micelle of detergents may sequester enzyme and block the substrate binding site to impede catalysis. Under physiological conditions, a lipid or membrane microenvironment may regulate enzymatic activity.     

Body Size,Growth and Life Span: Implications for the Polewards Range Shift of Octopus tetricus in South-Eastern Australia

Understanding the response of any species to climate change can be challenging. However, in short-lived species the faster turnover of generations may facilitate the examination of responses associated with longer-term environmental change. Octopus tetricus, a commercially important species, has undergone a recent polewards range shift in the coastal waters of south-eastern Australia, thought to be associated with the southerly extension of the warm East Australian Current. At the cooler temperatures of a polewards distribution limit, growth of a species could be slower, potentially leading to a bigger body size and resulting in a slower population turnover, affecting population viability at the extreme of the distribution. Growth rates, body size, and life span of O. tetricus were examined at the leading edge of a polewards range shift in Tasmanian waters (40°S and 147°E) throughout 2011. Octopus tetricus had a relatively small body size and short lifespan of approximately 11 months that, despite cooler temperatures, would allow a high rate of population turnover and may facilitate the population increase necessary for successful establishment in the new extended area of the range. Temperature, food availability and gender appear to influence growth rate. Individuals that hatched during cooler and more productive conditions, but grew during warming conditions, exhibited faster growth rates and reached smaller body sizes than individuals that hatched into warmer waters but grew during cooling conditions. This study suggests that fast growth, small body size and associated rapid population turnover may facilitate the range shift of O. tetricus into Tasmanian waters.     

Pulling or drilling, does size or species matter? An experimental study of prey handling in Octopus dierythraeus ()

The influence of both predator and prey size on the shift from a pulling to a drilling predatory response was examined in the intertidal octopus Octopus dierythraeus, using an experimental program. Additionally, selective drilling, where particular regions of the prey are targeted, was examined for a variety of bivalve and gastropod prey. O. dierythraeus always initially attempted to pull bivalves apart. Shells that were eventually drilled were always subjected to significantly more pulling attempts than those that could be pulled apart, indicating that octopus are willing to expend more energy to access the flesh quickly. There was no defined threshold where bivalve size caused an octopus to switch from a pulling to a drilling response. Instead, there was a broad size range where the octopus could adopt either handling method and it varied for each individual. Octopus may only able to pull open bivalves before the molecular ratchet or ‘catch’ mechanism that many bivalves possess is engaged. This might explain the lack of a relationship between either octopus or bivalve size and the success of pulling, as it is likely that when the bivalves were presented to individual octopus they were either setting the ‘catch’ mechanism, or had already engaged it. O. dierythraeus demonstrated selective drilling on a variety of molluscan prey, with penetration sites differing between prey species. O. dierythraeus targeted the valve periphery, which was the thinnest part of the shell, therefore minimizing handling time. O. dierythraeus always drilled gastropods, but did not target the thinnest regions of the shells, with drill site varying according to the morphology of the prey. Elongate species with pronounced aperture lips were drilled in the apical region, close to the columella on the side of the opercula whereas nonelongate species were drilled immediately above the aperture. The location of drilling sites may represent a trade-off between targeting the most effective places to inject paralyzing secretions and the mechanically simplest places to drill.     

Lisofylline prevents leak, but not neutrophil accumulation, in lungs of rats given IL-1 intratracheally

Hybertson, Brooks M., Stuart L. Bursten, Jonathan A. Leff,Young M. Lee, Eric K. Jepson, Chris R. Dewitt, John Zagorski, Hyun G. Cho, and John E. Repine. Lisofylline prevents leak, but not neutrophil accumulation, in lungs of rats given IL-1intratracheally. J. Appl. Physiol.82(1): 226-232, 1997.Interleukin-1 (IL-1) is increased in lunglavages from patients with the acute respiratory distress syndrome, andadministering IL-1 intratracheally causes neutrophil accumulation and aneutrophil-dependent oxidative leak in lungs of rats. In the presentstudy, we found that rats pretreated intraperitoneally with lisofylline[(R)-1-(5-hydroxyhexyl)-3,7-dimethylxanthine (LSF)], an inhibitor of lysophosphatidic acid acyl transferase, which reduces the production of unsaturated phosphatidic acid species,did not develop the lung leak or the related ultrastructural abnormalities that occur after intratracheal administration of IL-1.However, rats pretreated with LSF and then given IL-1 intratracheally did develop the same elevations of lung lavage cytokine-induced neutrophil chemoattractant (CINC) levels and the same increased numbersof lung lavage neutrophils as rats given IL-1 intratracheally. Lungs ofrats given IL-1 intratracheally also had increased unsaturated phosphatidic acid and free acyl (linoleate, linolenate) concentrations compared with untreated rats, and these lipid responses were prevented by pretreatment with LSF. Our results reveal that LSF decreases lungleak and lung lipid alterations without decreasing neutrophil accumulation or lung lavage CINC increases in rats given IL-1 intratracheally.

     

Ginkgolide B production in cultured cells derived from Ginkgo biloba L. leaves

Callus cultures and cell suspension cultures derived from Ginkgo biloba L. leaves produced ginkgolidc B. In cell suspension cultures, the production reached a maximum by the 13th day of subculture and followed by a sharp decrease. The medium of Murashige and Skoog induced the highest ginkgolide B content in cultures while the medium of Schenk and Hildebrandt promoted cell growth. For the maximal production of ginkgolide B, cells were cultured in Murashige and Skoog medium modified to contain 1.0 mg/l of -naphthaleneacetic acid, 0.1 mg/1 of kinetin, 30 g/1 sucrose and 1.25 mM potassium phosphate with a molar ratio of ammonium to nitrate ions of 1 3.Abbreviations B5 Gamborg et al (1968) medium - GKB Ginkgolide B - MS Murashige and Skoog (1962) medium - NAA -naphthaleneacetic aicd - SH Schenk and Hildebrandt (1972) medium     

Kinetic properties of a L-cysteine desulfhydrase-deficient mutant in the enzymatic formation of L-cysteine from D,L-ATC

Summary A mutant strain lacking in activity of L-cysteine desulfhydrase, a L-cysteine-decomposing enzyme, was screened after UV-treatment ofPseudomonas sp. CU6. The properties of the two strains, original and mutant, were compared on the basis of parameter values estimated from kinetic simulations of the enzymatic formation of L-cysteine from D,L-ATC. Both strains suffered from product inhibition, though inhibition was less for the mutant strain.     

Re-Identification on Korean Penicillium Sequences in GenBank Collected by Software GenMine

Penicillium species have been actively studied in various fields, and many new and unrecorded species continue to be reported in Korea. Moreover, unidentified and misidentified Korean Penicillium species still exist in GenBank. Therefore, it is necessary to revise the Korean Penicillium inventory based on accurate identification. We collected Korean Penicillium nucleotide sequence records from GenBank using the newly developed software, GenMine, and re-identified Korean Penicillium based on the maximum likelihood trees. A total of 1681 Korean Penicillium GenBank nucleotide sequence records were collected from GenBank. In these records, 1208 strains with four major genes (Internal Transcribed Spacer rDNA region, β-tubulin, Calmodulin and RNA polymerase II) were selected for Penicillium re-identification. Among 1208 strains, 927 were identified, 82 were identified as other genera, the rest remained undetermined due to low phylogenetic resolution. Identified strains consisted of 206 Penicillium species, including 156 recorded species and 50 new species candidates. However, 37 species recorded in the national list of species in Korea were not found in GenBank. Further studies on the presence or absence of these species are required through literature investigation, additional sampling, and sequencing. Our study can be the basis for updating the Korean Penicillium inventory.     

Isolation and functional analysis of a 24-residue linear alpha-helical antimicrobial peptide from Korean blackish cicada, Cryptotympana dubia (Homoptera)

A new antimicrobial peptide, cryptonin, was isolated and characterized from the adult Korean blackish cicada, Cryptotympana dubia. It consists of 24 amino acid residues and has a molecular weight of 2,704 Da on mass spectroscopy. The predicted alpha-helical structure analysis and increased helix percent in 40% trifloroethanol of cryptonin suggests that it belongs to the typical linear alpha-helix forming peptide. Binding of the biotin-labeled cryptonin at the surface of E. coli cells and increased influx of propidium iodide in E. coli after cryptonin treatment indicates that it kills microbial cells by binding bacterial cell surfaces and disrupting the cell permeability. Cryptonin showed strong antibacterial (MIC 1.56-25 microg/ml) and antifungal (MIC 3.12-50 microg/ml) activities against tested bacteria and fungi including two antibiotic-resistant bacterial strains; methicilin-resistant S. aureus and vancomycin-resistant Enterococci (MIC 25 microg/ml, each).