Web-service based information integration for e-mortgage contract matchmaking decision support: A case study in Hong Kong

Effective decision making often requires disparate information from heterogeneous sources. When significant contracts are involved, gathering such information is particularly slow and inefficient. As real estate business plays an important role in Hong Kong economy, there is a strong need for a handy and efficient service to assist the mortgage searching activities. Presently, a property buyer lacks of the mortgage information for the interested property when making the purchase decision. Many buyers can only search for the property mortgage after a down payment is made because of keen competitions in purchasing. However, sometimes the bank cannot offer the mortgage plan as the buyer expected because of the buyer's financial status, property valuation, and price trend. Therefore, we study on the requirements of an e-Mortgage Contract Matchmaking Service (EMS) for offering it in the form of a Web service via real estate agencies to the buyers. The EMS can be incorporated into the agency's property management system so that the relevant mortgage information (provided by the participant financial institutions) could be revealed when the buyer is making the purchase decision. Moreover, the EMS offers mortgage contract evaluation and ranking to assists the prospective buyer earlier in the decision-making stage. © 2006 IEEE

Characterization of CpdC, a large-ring lactone-hydrolyzing enzyme from Pseudomonas sp. strain HI-70, and its use as a fusion tag facilitating overproduction of proteins in Escherichia coli

There are few entries of carbon-carbon bond hydrolases (EC 3.7.1.-) in the ExPASy database. In microbes, these enzymes play an essential role in the metabolism of alicyclic or aromatic compounds as part of the global carbon cycle. CpdC is a\u3c9-pentadecalactone hydrolase derived from the degradation pathway of cyclopentadecanol or cyclopentadecanone by Pseudomonas sp. strain HI-70. CpdC was purified to homogeneity and characterized. It is active as a dimer of 56,000 Da with a subunit molecular mass of 33,349. Although CpdC has the highest activity and reaction rate (kcat) toward\u3c9-pentadecalactone, its catalytic efficiency favors lauryl lactone as a substrate. The melting temperature (Tm) of CpdC was estimated to be 50.9\ub10.1\ub0C. The half-life of CpdC at 35\ub0C is several days. By virtue of its high level of expression in Escherichia coli, the intact CpdC-encoding gene and progressive 3=-end deletions were employed in the construction of a series of fusion plasmid system. Although we found them in inclusion bodies, proof-of-concept of overproduction of three microbial cutinases of which the genes were otherwise expressed poorly or not at all in E. coli was demonstrated. On the other hand, two antigenic proteins, azurin and MPT63, were readily produced in soluble form. \ua9 2013, American Society for Microbiology.Peer reviewed: YesNRC publication: Ye

2-Nitrobenzoate 2-Nitroreductase (NbaA) switches its substrate specificity from 2-Nitrobenzoic acid to 2,4-Dinitrobenzoic acid under oxidizing conditions

2-Nitrobenzoate 2-nitroreductase (NbaA) of Pseudomonas fluorescens strain KU-7 is a unique enzyme, transforming 2-nitrobenzoic acid (2-NBA) and 2,4-dinitrobenzoic acid (2,4-DNBA) to the 2-hydroxylamine compounds. Sequence comparison reveals that NbaA contains a conserved cysteine residue at position 141 and two variable regions at amino acids 65 to 74 and 193 to 216. The truncated mutant \u39465-74 exhibited markedly reduced activity toward 2,4-DNBA, but its 2-NBA reductionactivity was unaffected; however, both activities were abolished in the \u394193-216 mutant, suggesting that these regions are necessary for the catalysis and specificity of NbaA. NbaA showed different lag times for the reduction of 2-NBA and 2,4-DNBA with NADPH, and the reduction of 2,4-DNBA, but not 2-NBA, failed in the presence of 1mMdithiothreitol or under anaerobic conditions, indicating oxidative modification of the enzyme for 2,4-DNBA. The enzyme was irreversibly inhibited by 5,5'-dithio-bis-(2-nitrobenzoic acid) and ZnCl2, which bind to reactive thiol/thiolate groups, and was eventually inactivated during the formation of higherorder oligomers at high pH, high temperature, or in the presence of H2O2. SDS-PAGE and mass spectrometry revealed the formation of intermolecular disulfide bonds by involvement of the two cysteines at positions 141 and 194. Site-directed mutagenesis indicated that the cysteines at positions 39, 103, 141, and 194 played a role in changing the enzyme activity and specificity toward 2-NBA and 2,4-DNBA. This study suggests that oxidative modifications of NbaA are responsible for the differential specificity for the two substrates and further enzyme inactivation through the formation of disulfide bonds under oxidizing conditions. \ua9 2013, American Society for Microbiology.Peer reviewed: YesNRC publication: Ye

Styrene, an Unpalatable Substrate with Complex Regulatory Networks

Styrene, a volatile organic compound (VOC), is an important industrial material involved in the production of plastic, synthetic rubber and resin, insulation and other industrial materials containing molecules such as polystyrene, butadiene-styrene latex, styrene copolymers and unsaturated polyester resins. Styrene exposure may cause contact-based skin inflammation, irritation of eyes, nose and respiratory tract. Neurological effects such as alterations in vision, hearing loss and longer reaction times, have been associated with styrene exposure in the workplace. In addition, styrene oxide may act as an established mutagen and carcinogen (www.epa.gov/chemfact/styre-sd.pdf). It has been reported that, in 2002, 22,323 tons of styrene were released to the environment (82), in spite of the US Clean Air Act mandate on reduction in the volume of allowable styrene emission (www.epa.gov/chemfact/styre-sd.pdf). Among a variety of emerging air pollution technologies, biofiltration is an attractive option for the treatment of VOCs, because it is cost-effective and does not generate secondary contaminants (45). Moreover, microbial biodegradation is the major route for the removal of non-aqueous compounds from soils. Styrene is also naturally present in non polluted environments, since it derives from fungal decarboxylation of cinnamic acid (90). Therefore it is not surprising that microorganisms of different families have been found to be able to degrade this compound (31). The promising results obtained in the removal of styrene from contaminated waste-gases by biofiltration (5, 39, 103) have led to an increasing attention to the regulatory mechanisms underlying styrene degradation, with the aim to improve bioremediation processes. Despite the diffusion in nature of this degradative capability, only few strains, mainly belonging to the Pseudomonas genus, have been characterized (66). This chapter is focused on the up-to-now discovered regulatory mechanisms underlying the expression of the styrene-catabolism genes. Moreover, open questions on environmental and metabolic constrains that govern styrene degradation are discussed. Biotechnological relevance of styrene-degrading strains in fine chemicals production and bioremediation processes is not examined here. Main topics on these application fields have recently been reviewed by Dobson and co-workers (66)