Asian Science Citation Index is committed to provide an authoritative, trusted and significant information by the coverage of the most important and influential journals to meet the needs of the global scientific community.  
ASCI Database
308-Lasani Town,
Sargodha Road,
Faisalabad, Pakistan
Fax: +92-41-8815544
Contact Via Web
Suggest a Journal
 
Articles by H Kajiwara
Total Records ( 2 ) for H Kajiwara
  T Mine , S Katayama , H Kajiwara , M Tsunashima , H Tsukamoto , Y Takakura and T. Yamamoto
 

We cloned, expressed, and characterized a novel β-galactoside 2,6-sialyltransferase from Photobacterium leiognathi strain JT-SHIZ-119. The protein showed 56–96% identity to the marine bacterial 2,6-sialyltransferases classified into glycosyltransferase family 80. The sialyltransferase activity of the N-terminal truncated form of the recombinant enzyme was 1477 U/L of Escherichia coli culture. The truncated recombinant enzyme was purified as a single band by sodium dodecyl sulfate polyacrylamide gel electrophoresis through 3 column chromatography steps. The enzyme had distinct activity compared with known marine bacterial 2,6-sialyltransferases. Although 2,6-sialyltransferases cloned from marine bacteria, such as Photobacterium damselae strain JT0160, P. leiognathi strain JT-SHIZ-145, and Photobacterium sp. strain JT-ISH-224, show only 2,6-sialyltransferase activity, the recombinant enzyme cloned from P. leiognathi strain JT-SHIZ-119 showed both 2,6-sialyltransferase and 2,6-linkage-specific neuraminidase activity. Our results provide important information toward a comprehensive understanding of the bacterial sialyltransferases belonging to the group 80 glycosyltransferase family in the CAZy database.

  Y Kushi , H Kamimiya , H Hiratsuka , H Nozaki , H Fukui , M Yanagida , M Hashimoto , K Nakamura , S Watarai , T Kasama , H Kajiwara and T. Yamamoto
 

Bacterial sialyltransferases (STs) from marine sources were characterized using glycosphingolipids (GSLs). Bacterial STs were found to be β-galacotoside STs. There were two types of STs: (1) ST obtained from strains such as ishi-224, 05JTC1 (#1), ishi-467, 05JTD2 (#2), and faj-16, 05JTE1 (#3), which form 2-3 sialic acid (Sia) linkages, named 2-3ST, (2) ST obtained from strains such as ISH-224, N1C0 (#4), pda-rec, 05JTB2 (#5), and pda-0160, 05JTA2 (#6), which form 2-6 Sia linkages, named 2-6ST. All STs showed affinity to neolacto- and lacto-series GSLs, particularly in neolactotetraosyl ceramide (nLc4Cer). No large differences were observed in the pH and temperature profiles of enzyme activities. Kinetic parameters obtained by Lineweaver–Burk plot analysis showed that #3 and #4 STs had practical synthetic activity and thus it became easily possible to achieve large-scale ganglioside synthesis (100–300 µM) using these recombinant enzymes. Gangliosides synthesized from nLc4Cer by 2-3 and 2-6STs were structurally characterized by several analytical and immunological methods, and they were identified as IV3NeuAc-nLc4Cer(S2-3PG) and IV6NeuAc-nLc4Cer (S2-6PG), respectively. Further characterization of these STs using lactotetraosylceramide (Lc4Cer), neolactohexaosylceramide (i antigen), and IV6kladoLc8Cer (I antigen) showed the synthesis of corresponding gangliosides as well. Synthesized gangliosides showed binding activity to the influenza A virus [A/panama/2007/99 (H3N2)] at a similar level to purified S2-3PG and S2-6PG from mammalian sources. The above evidence suggests that these STs have unique features, including substrate specificities restricted to lacto- and neolactoseries GSLs, as well as catalytic potentials for ganglioside synthesis. This demonstrates that efficient in vitro ganglioside synthesis could be a valuable tool for selectively synthesizing Sias modifications, thereby permitting the exploration of unknown functions.

 
 
 
Copyright   |   Desclaimer   |    Privacy Policy   |   Browsers   |   Accessibility