Abstract
Hyaluronic acid (hyaluronan) is a high molecular weight glycosaminoglycan composed of repeating disaccharides of glucuronic acid and N-acetylglucosamine. The molecular weight of hyaluronan is important for its rheological property, biological function, and application. However, genes important for regulation of hyaluronan production or molecular weight remain poorly understood. Here, we address the roles of two predicated hyaluronate lyase-encoding genes, hylB and hylZ in Streptococcus zooepidemicus. Semi-quantitative RT-PCR assays showed that hylZ was constitutively expressed while the expression level of hylB was growth-phase dependent. Using recombinantly expressed 6His-HylB and -HylZ protein, enzyme assays revealed that HylB was a hyaluronate lyase, and its K m and V max were 0.57 μM and 1.43 mM min−1, respectively. 6His-HylZ showed no activity against hyaluronan while it hydrolyzed pNp-β-GlcNAc suggesting that HylZ was a beta-N-acetylglucosaminidase. Under the optimal conditions (pH 6.0 and 50 °C), the K m and V max for 6His-HylZ to degrade pNp-β-GlcNA were 1.16 mM and 26.18 μmol min−1 mg−1, respectively. Characterization of ΔhylB and ΔhylZ demonstrated that loss of hylB or/and hylZ had no significant effects on cell growth, lactic acid, and hyaluronan yields. Significantly, as compared to the wild type, ΔhylB produced hyaluronan with an 18 % increase in molecular weight. Our results strongly suggest that hylB encodes a hyaluronate lyase while hylZ encodes a β-N-acetylglucosaminidase. hylB-deficient strain has the potential to produce high molecular weight hyaluronan.



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Armstrong DC, Johns MR (1997) Culture conditions affect the molecular weightproperties of hyaluronic acid produced by Streptococcus zooepidemicus. Appl Environ Microbiol 63(7):2759–2764
Beres SB, Sesso R, Pinto SWL, Hoe NP, Porcella SF, DeLeo FR, Musser JM (2008) Genome sequence of a Lancefield group C Streptococcus zooepidemicus strain causing epidemic nephritis: new information about an old disease. PLoS ONE 3(8):e3026
Bitter T, Muir HM (1962) A modified uronic acid carbazole reaction. Anal Biochem 4(4):330–334
Blank LM, McLaughlin RL, Nielsen LK (2005) Stable production of hyaluronic acid in Streptococcus zooepidemicus chemostats operated at high dilution rate. Biotechnol Bioeng 90(6):685–693
Canard B, Garnier T, Saint-Joanis B, Cole ST (1994) Molecular genetic analysis of the nagH gene encoding a hyaluronidase of Clostridium perfringens. Mol Gen Genet 243(2):215–224
Chen S-J, Chen J-L, Huang W-C, Chen H-L (2009) Fermentation process development for hyaluronic acid production by Streptococcus zooepidemicus ATCC 39920. Korean J Chem Eng 26(2):428–432
Chen WY, Marcellin E, Hung J, Nielsen LK (2009) Hyaluronan molecular weight is controlled by UDP-N-acetylglucosamine concentration in Streptococcus zooepidemicus. J Biol Chem 284(27):18007–18014
Choi KH, Seo JY, Park KM, Park CS, Cha J (2009) Characterization of glycosyl hydrolase family 3 beta-N-acetylglucosaminidases from Thermotoga maritima and Thermotoga neapolitana. J Biosci Bioeng 108(6):455–459
Chong BF, Blank LM, Mclaughlin R, Nielsen LK (2005) Microbial hyaluronic acid production. Appl Microbiol Biotechnol 66(4):341–351
Comtesse N, Maldener E, Meese E (2001) Identification of a nuclear variant of MGEA5, a cytoplasmic hyaluronidase and a β-N-acetylglucosaminidase. Biochem Biophys Res Commun 283(3):634–640
Guo X, Liu F, Zhu X, Su Y, Ling P (2009) Expression of a novel hyaluronidase from Streptococcus zooepidemicus in Escherichia coli and its application for the preparation of HA oligosaccharides. Carbohydr Polym 77(2):254–260
Heldin P, Laurent TC, Ernst B, Hart GW, Sinaý P (1999) Biosynthesis of hyaluronan. Carbohydr Chem Biol 363–374
Hengen PN (1995) Purification of His-Tag fusion proteins from Escherichia coli. Trends Biochem Sci 20(7):285–286
Kogan G, Šoltés L, Stern R, Gemeiner P (2007) Hyaluronic acid: a natural biopolymer with a broad range of biomedical and industrial applications. Biotechnol Lett 29(1):17–25
Laurent TC, Ryan M, Pietruszkiewicz A (1960) Fractionation of hyaluronic acid the polydispersity of hyaluronic acid from the bovine vitreous body. Biochim Biophys Acta 42:476–485
Liu H, Suresh A, Willard FS, Siderovski DP, Lu S, Naqvi NI (2007) Rgs1 regulates multiple Gα subunits in Magnaporthe pathogenesis, asexual growth and thigmotropism. EMBO J 26(3):690–700
Liu L, Du G, Chen J, Wang M, Sun J (2009) Comparative study on the influence of dissolved oxygen control approaches on the microbial hyaluronic acid production of Streptococcus zooepidemicus. Bioprocess Biosyst Eng 32(6):755–763
Ma Z, Geng J, Zhang H, Yu H, Yi L, Lei M, Lu C-P, Fan H-J, Hu S (2011) Complete Genome Sequence of Streptococcus equi subsp. zooepidemicus strain ATCC 35246. J Bacteriol 193(19):5583–5584
Mangan J, Sole K, Mitchison D, Butcher P (1997) An effective method of RNA extraction from bacteria refractory to disruption, including mycobacteria. Nucleic Acids Res 25(3):675–676
Muckenschnabel I, Bernhardt G, Spruss T, Dietl B, Buschauer A (1998) Quantitation of hyaluronidases by the Morgan-Elson reaction: comparison of the enzyme activities in the plasma of tumor patients and healthy volunteers. Cancer Lett 131(1):13–20
Sheldon W, Macauley M, Taylor E, Robinson C, Charnock S, Davies G, Vocadlo D, Black G (2006) Functional analysis of a group A streptococcal glycoside hydrolase Spy1600 from family 84 reveals it is beta-N-acetylglucosaminidase and not a hyaluronidase. Biochem J 399:241–247
Sun X, Yang D, Wang Y, Geng H, He X, Liu H (2013) Development of a markerless gene deletion system for Streptococcus zooepidemicus: functional characterization of hyaluronan synthase gene. Appl Microbiol Biotechnol 97(19):8629–8636
Acknowledgments
This work was supported by grants from the 7th Singapore-China JRP (2011DFA31280), Tianjin Scientific Project (13RCGFSY19400), and the 863 project (2012AA020403).
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Sun, X., Wang, Z., Bi, Y. et al. Genetic and Functional Characterization of the Hyaluronate Lyase HylB and the Beta-N-Acetylglucosaminidase HylZ in Streptococcus zooepidemicus . Curr Microbiol 70, 35–42 (2015). https://doi.org/10.1007/s00284-014-0679-4
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DOI: https://doi.org/10.1007/s00284-014-0679-4


