Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.23 (beta-galactosidase)
 14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A halotolerant bacterium was isolated from a saline lake located in Mallorca, Spain. Cells of the strain, designated MACL01T, were Gram-negative, rod-shaped and motile by means of polar flagella. Colonies of strain MACL01T were white to cream in TSA medium, turning brown after 7 days of incubation; they were blue in thiosulphate/citrate/bile salts/sucrose agar medium. A neighbour-joining phylogenetic analysis based on 16S rRNA gene sequences showed that strain MACL01T belongs to the genus Photobacterium, in which it forms a distinct lineage together with Photobacterium rosenbergii and Photobacterium ganghwense (showing 96.9 and 96.2 % similarity, respectively). The most closely related taxon according to phylogenetic analysis of the rpoA gene is also P. rosenbergii (90 % similarity). The recA gene also showed low similarity (83.7, 83.4 and 82.4 %, respectively) with respect to those of Vibrio proteolyticus LMG 3772T, Photobacterium leiognathii LMG 4228T and P. rosenbergii LMG 22223T. Neighbour-joining phylogenetic analysis of the rpoA and recA genes confirms that strain MACL01T belongs to the genus Photobacterium, forming a branch together with P. rosenbergii. Strain MACL01T was able to grow in 0-8 % NaCl. Growth occurred between 4 and 37 degrees C (optimum, 28 degrees C) and at pH 5-8.5. Luminescence was negative on marine agar. Strain MACL01T was found to be sensitive to the vibriostatic agent O/129. It reduced nitrate to nitrite, produced beta-galactosidase and hydrolysed gelatin, but did not produce arginine dihydrolase, indole or acetoin. Strain MACL01T used several carbohydrates and fermented glucose, L-arabinose and sucrose. The most abundant fatty acids were summed feature 3 (32.6 %; comprising C16 : 1omega7c and/or C15 : 0 iso 2-OH), C16 : 0 (21.2 %) and C18 : 1omega7c (19.9 %). The G+C content of the genomic DNA was 49.8 mol%. On the basis of genotypic, phenotypic, chemotaxonomic and phylogenetic results, strain MACL01T (=LMG 22194T=CECT 5860T) should be classified as the type strain of a novel species of the genus Photobacterium, for which the name Photobacterium halotolerans sp. nov. is proposed.
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PMID:Photobacterium halotolerans sp. nov., isolated from Lake Martel in Spain. 1662 56

We find that peptides containing -Asn-Gly- sequences typically show approximately 70-80% degree of deamidation after standard overnight (approximately 12 h) tryptic digestion at 37 degrees C. This emphasizes the need for more detailed information about the deamidation reaction in -Asn-Gly- sequences, in which two deamidated species are produced, one containing an aspartic acid (-Asp-Gly-) residue and the other containing an isoaspartic acid (-betaAsp-Gly-) residue. For the peptide SLNGEWR (54-60 beta-galactosidase, E. coli), all three components of the reaction mixture were separated by HPLC on C18 300-A sorbent, with trifluoroacetic acid as an ion-pairing modifier. Their intensity ratios suggested the elution order -betaAsp-/-Asn-/-Asp-, which was subsequently confirmed by MALDI MS and MS/MS analysis. The kinetics of the deamidation was studied in detail for the synthetic SLNGEWR parent using RP HPLC with UV detection. The half-life of this peptide was found to be approximately 8 h under digestion conditions. Analysis of a large pool of peptide retention data shows that the -betaAsp-/-Asn-/ -Asp- retention order is normally observed under the above conditions, especially if the original -NG- sequence is surrounded by hydrophobic amino acids. However, changing chromatographic conditions to 100-A pore size sorbents, or using formic acid as a modifier, increases the retention time of -betaAsp- relative to the -Asn-/-Asp- pair, so the order can sometimes be different.
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PMID:Deamidation of -Asn-Gly- sequences during sample preparation for proteomics: Consequences for MALDI and HPLC-MALDI analysis. 1697 Mar 46

The synthesis and properties of gemini surfactants of the type (R(1)(CO)-Lys(H)-NH)2(CH2)n are reported. For a spacer length of n = 6, the hydrophobic acyl tail was varied in length (R(1) = C8, C10, C12, C14, C16, and C18) and, for R(1) = C18, the degree of unsaturation. For R(1)(CO) = oleoyl (C18:1 Z) the spacer length (n = 2-8) and the stereochemistry of the lysine building block were varied; a 'half-gemini' derivative with a single oleoyl tail and head group was also prepared. The potential of the gemini surfactants to transfer polynucleotides across a cell membrane was investigated by transfection of HeLa cells with beta-galactosidase, both in the presence and absence of the helper lipid DOPE. Oleoyl was found to be by far the best hydrophobic tail for this biological activity, whereas the effect of the lysine stereochemistry was less pronounced. The effect of an optimum spacer length (n = 6) was observed only in the absence of helper lipid. The most active surfactant, i.e. the one with oleoyl chains and n = 6, formed liposomes with sizes in the range of 60-350 nm, and its lipoplex underwent a transition from a lamellar to a hexagonal morphology upon lowering the pH from 7 to 3.
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PMID:Structure-delivery relationships of lysine-based gemini surfactants and their lipoplexes. 2496 40


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