Valorization of Lipopeptides Biosurfactants as Anticancer Agents

International Journal of Peptide Research and Therapeutics - Biosurfactants are natural compounds produced biologically by certain bacterial strains. They are promising alternatives in several...     

The effect of viscosity,friction, and sonication on the morphology and metabolite production from Aspergillus terreus ATCC 20542

Bioprocess and Biosystems Engineering - This study investigates the effects of viscosity, friction, and sonication on the morphology and the production of lovastatin, (+)-geodin, and sulochrin by...     

Regeneration im Pankreas der Ratte nach Alloxanschädigung

Zusammenfassung Im Pankreas ausgewachsener Ratten wurden nach Alloxanschädigung Regenerationsherde beobachtet und beschrieben. Sie bestehen in einem büschelförmigen Aussprossen kleiner Gänge an umschriebenen Stellen des Organes, die in ein retikuläres Bindegewebe eingebettet sind. In analoger Weise wie bei der ontogenetischen Entwicklung des Pankreas aus den primitiven Drüsenschläuchen, kommt es auch im Bereiche der Gangwucherungen zur Neubildung von Inselgewebe.     

A fed-batch strategy to produce high poly(3-hydroxybutyrate-co-3-hydroxyvalerate-co-4-hydroxybutyrate) terpolymer yield with enhanced mechanical properties in bioreactor

Bioprocess and Biosystems Engineering - This study reports an efficient fed-batch strategy to improve poly(3-hydroxybutyrate-co-3-hydroxyvalerate-co-4-hydroxybutyrate) [P(3HB-co-3HV-co-4HB)]...     

Improving reactive ink jet printing via cationization of cellulosic linen fabric

Cellulose linen fabric samples subjected to cationization using different cationizing agents: dodecyl trimethyl ammonium bromide (DTAB), tetra methyl ammonium hydroxide (TMAH), and Quat-188, via pad batch technique, followed by ink jet printing with reactive dyes.     

Molten Globule-Triggered Inactivation of a Thermostable and Solvent Stable Lipase in Hydrophilic Solvents

The use of lipase in hydrophilic solvent is usually hampered by inactivation. The solvent stability of a recombinant solvent stable lipase isolated from thermostable Bacillus sp. strain 42 (Lip 42), in DMSO and methanol were studied at different solvent-water compositions. The enzymatic activities were retained in up to 45% v/v solvent compositions. The near-UV CD spectra indicated that tertiary structures were perturbed at 60% v/v and above. Far-UV CD in methanol indicated the secondary structure in Lip 42 was retained throughout all solvent compositions. Fluorescence studies indicated formations of molten globules in solvent compositions of 60% v/v and above. The enzyme was able to retain its secondary structures in the presence of methanol; however, there was a general reduction in β-sheet and an increase in α-helix contents. The H-bonding arrangements triggered in methanol and DMSO, respectively, caused different forms of tertiary structure perturbations on Lip 42, despite both showing partial denaturation with molten globule formations.     

Chemistry and conformation of vitamin D molecules

1,25-Dihydroxyvitamin D₃ (1,25) is a structurally unique steroid hormone because it not only possesses the complete 25-hydroxycholesterol side chain, but most notably, it possesses a seco-B triene structure (it lacks a B-ring and is usually depicted in a non-steroidal, extended conformation). In contrast, the classical steroid hormones possess a truncated side chain (progesterone, cortisol, and aldosterone) or no side chain (estradiol and testosterone) and they all possess the fully intact ABCD steroid rings. These structural differences render the seco-B-steroid 1,25 considerably more conformationally flexible. Since 1,25 is now known to target a myriad of tissues where specific interactions occur to produce an array of biological responses, it is of interest to determine whether different topologies of 1,25 (resulting from different conformational orientations of 1,25) are necessary to interact effectively at the different target sites. The array of biological responses include both non-genomic and genomic effects and there is considerable promise for the efficacy of 1,25 analogs as chemotherapeutic agents in a variety of human disease states. For the non-genomic calcium transport response of transcaltachia, the finding that two 6-s-cis locked analogs, 1,25-dihydroxyprevitamin D₃ (pre-1,25) and 1,25-dihydroxylumisterol₃ (1,25-Lumi), are equipotent to 1,25, points strongly to the involvement of the 6-s-cis conformer of 1,25 as the biologically active conformer. Since there is a continuum of easily interconvertible 6,7-single bond conformers of the seco-B ring available to 1,25, conformational minima (either local or global) may have little to do with the manner in which 1,25 is bound to receptor. For the genomic calcium transport response, and for other genomic (or non-genomic) effects, there is no clear evidence whether the steroidal (s-cis) or non-steroidal (s-trans) conformer of 1,25 is involved. In order to address this matter further, efforts are underway to evaluate other conformationally locked analogs of 1,25 which might mimic either the planar 6-s-trans-1,25 or some intermediate conformer between it and the planar-6-s-cis form.