The miracle of microarray data analysis

A report on the tenth Annual Bioinformatics and Genome Research meeting of the Cambridge Healthtech Institute's Beyond Genome 2001 series, San Francisco, USA, 17-19 June 2001.     

Discovery of a new inhibitor lead of adenovirus proteinase: steps toward selective, irreversible inhibitors of cysteine proteinases

Using the computer docking program EUDOC, in silico screening of a chemical database for inhibitors of human adenovirus cysteine proteinase (hAVCP) identified 2,4,5,7-tetranitro-9-fluorenone that selectively and irreversibly inhibits hAVCP in a two-step reaction: reversible binding (Ki = 3.09 microM) followed by irreversible inhibition (ki = 0.006 s(-1)). The reversible binding is due to molecular complementarity between the inhibitor and the active site of hAVCP, which confers the selectivity of the inhibitor. The irreversible inhibition is due to substitution of a nitro group of the inhibitor by the nearby Cys122 in the active site of hAVCP. These findings suggest a new approach to selective, irreversible inhibitors of cysteine proteinases involved in normal and abnormal physiological processes ranging from embryogenesis to apoptosis and pathogen invasions.     

Compositional changes of cottonseed hull substrate during P. ostreatus growth and the effects on the feeding value of the spent substrate

The enzymic synthesis of alkyl-beta-glucosides by water-immiscible alcohols was studied in stirred flasks as well as in a tubular enzymatic reactor. In the first case, direct alkylation of beta-D-glucose from hexanol using immobilized beta-glycosidase gave a higher conversion yield and final product concentration than that using the enzyme in its free state (yield 10 against 8% mol/mol, concentration 2 against 1.6 g/l). Direct glycosylation of beta-D-glucose from hexanol resulted in a higher reaction performance (yield 10%) than that from octanol (yield 5%). However, the two different incubation temperatures tested (37 degrees C and 50 degrees C), showed no significant differences concerning final product concentrations. The more interesting results were obtained by transglycosylation of methyl-1-beta-glucose from hexanol, with a conversion yield of 21% mol/mol (product amount 4 g/l). However, the transgalactosylation of lactose from hexanol, catalyzed by a fungal beta-galactosidase, showed only a feeble reactivity. The feasibility of enzymic alkylation was also tested in a tubular enzymatic reactor; hexyl-1-beta-glucoside was produced via direct glycosylation from hexanol catalyzed by free beta-glycosidase with a final concentration 1.3-2.3 g/l and a yield varying between 11% and 20% mol/mol.     

Prolonged membrane potential depolarization in cingulate pyramidal cells after digit amputation in adult rats

The anterior cingulate cortex (ACC) plays an important role in higher brain functions including learning, memory, and persistent pain. Long-term potentiation of excitatory synaptic transmission has been observed in the ACC after digit amputation, which might contribute to plastic changes associated with the phantom pain. Here we report a long-lasting membrane potential depolarization in ACC neurons of adult rats after digit amputation in vivo. Shortly after digit amputation of the hind paw, the membrane potential of intracellularly recorded ACC neurons quickly depolarized from ~-70 mV to ~-15 mV and then slowly repolarized. The duration of this amputation-induced depolarization was about 40 min. Intracellular staining revealed that these neurons were pyramidal neurons in the ACC. The depolarization is activity-dependent, since peripheral application of lidocaine significantly reduced it. Furthermore, the depolarization was significantly reduced by a NMDA receptor antagonist MK-801. Our results provide direct in vivo electrophysiological evidence that ACC pyramidal cells undergo rapid and prolonged depolarization after digit amputation, and the amputation-induced depolarization in ACC neurons might be associated with the synaptic mechanisms for phantom pain.     

Nucleotide sequences in the RNA of mammalian leukemia and sarcoma viruses.

The nucleotide sequences in viral RNA from purified murine sarcoma and hamster leukemia viruses (S+H+) from HTG-1 cells and Rauscher leukemia virus (RLV) from JLS-V 9 cells have been examined by polynucleotide agarose affinity chromatography. There is at least one copy of poly(A) sequences per genomic viral RNA molecule. After heat denaturation of genomic viral RNA (S+H+), there are two types of viral subunits for 34S and 28S species: one that contains poly(A) sequences and one that does not. There are no detectable poly(U) tracts in the viral RNA. However, poly(C) sequences and poly(G) tracts were detected in viral RNA, although less poly(G) than poly(C) tracts were observed. In addition, heat-denatured genomic viral RNA has a greater affinity for poly(G) agarose column than native genomic viral RNA.     

Citrus Vascular Proteomics Highlights the Role of Peroxidases and Serine Proteases during Huanglongbing Disease Progression

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Highlights

• •HLB is the most devastating citrus disease associated with the pathogen CLas.
• •Proteases and peroxidases accumulated in plant vascular tissue after CLas infection.
• •Dynamic changes in serine protease activity occur across genotypes and environments.