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The variable lymphocyte receptor (VLR) B of jawless vertebrates functions as a secreted Ab of jawed vertebrates and has emerged as an alternative Ab with a single polypeptide chain. After observing an upregulated VLRB response in hagfish immunized with avian influenza virus (AIV) subtype H9N2, we screened AIV H9N2–specific VLRB using a mammalian expression system. To improve the binding avidity of the Ag-specific VLRB to the Ag, we enabled multimerization of the VLRB by conjugating it with C-terminal domain of human C4b-binding protein. To dramatically enhance the expression and secretion of the Ag-specific VLRB, we introduced a glycine–serine linker and the murine Ig κ leader sequence. The practical use of the Ag-specific VLRB was also demonstrated through various immunoassays, detected by anti-VLRB Ab (11G5). Finally, we found that the Ag-specific VLRB decreased the infectivity of AIV H9N2. Together, our findings suggest that the generated Ag-specific VLRB could be used for various immunoapplications.

In hagfish and lampreys, two representative jawless vertebrates, the humoral immunity is directly mediated by variable lymphocyte receptors B (VLRBs). Both monomeric VLRBs are structurally and functionally similar, but their C-terminal tails differ: lamprey VLRB has a Cys-rich tail that forms disulfide-linked pentamers of dimers, contributing to its multivalency, whereas hagfish VLRB has a superhydrophobic tail of unknown structure. Here, we reveal that VLRBs obtained from hagfish plasma have a globular-shaped multimerized form (approximately 0.6 to 1.7 MDa) that is generated by hydrophobic clustering instead of covalent linkage. Electron microscopy (EM) and single-particle analysis showed that the multimerized VLRBs form globular-shaped clusters with an average diameter of 28.7 ± 2.2 nm. The presence of VLRBs in the complex was confirmed by immune-EM analysis using an anti-VLRB antibody. Furthermore, the hydrophobic hagfish C-terminus (HC) was capable of triggering multimerization and directing the cellular surface localization via a glycophosphatidylinositol linkage. Our results strongly suggest that the hagfish VLRB forms a previously unknown globular-shaped antibody. This novel identification of a structurally unusual VLRB complex may suggest that the adaptive immune system of hagfish differs from that of lamprey.

The handling of generated sludge waste during polymer production is one of the main environmental concerns of the polymer industry. An alternative filtration technique was applied to determine the efficiency of different types of filtering media for polymer production. A vibration filter media was replaced with a non-woven fabric filter that was previously used in the refining facility. The purpose of this study is to analyze how much the new filtration affects sludge generation and final production. The application of these alternative filtration techniques have resulted in a significant reduction in the amount of non-recyclable sludge by approximately 77%, while the total amount of polymer production has increased by 41% during the six-year study period. The refining facility saved a total of 617,710 USD/y by changing the filtration system, resulting in an increase in product recovery and a decrease in sludge generation, as well as an improvement in reaction conditions.

An approximate string-matching algorithm is described based on earlier attribute-matching algorithms. The algorithm involves building a trie from the text string which takes time O(N log2 N), for a text string of length N. Once this data structure has been built any number of approximate searches can be made for pattern strings of length m. The expected complexity analysis is given for the look-up phase of the algorithm based on certain regularity assumptions about the background language. The expected look-up time for each pattern is O(m log2 N). The ideas employed in the algorithm have been shown effective in practice before, but have not previously received any theoretical analysis.