Dextran molecular size and degree of branching as a function of sucrose concentration, pH, and temperature of reaction of Leuconostoc mesenteroides B-512FMCM dextransucrase.
Reactions of Leuconostoc mesenteroides B-512FMCM dextransucrase with increasing concentrations of sucrose, from 0.1 to 4.0 M, gave a decreasing amount of high-molecular weight dextran (HMWD) (>10(6) Da) with a concomitant increase in low-molecular weight dextran (LMWD) (<10(5) Da). At 0.1 M sucrose, pH 5.5, and 28 degrees C, 99.8% of the dextran had a MW>10(6) Da and at 4.0 M sucrose, 69.9% had a MW<10(5) Da and 30.1% had a MW>10(6) Da, giving a bimodal distribution. The degree of branching increased from 5% for 0.1 M sucrose to 16.6% for 4.0 M sucrose. The temperature had very little effect on the size of the dextran, which was >10(6) Da, but it had a significant effect on the degree of branching, which was 4.8% at 4 degrees C and increased to 14.7% at 45 degrees C. Both the molecular weight (MW) and the degree of branching were not significantly affected by different pH values between 4.5 and 6.0.
Faculty of Applied Chemical Engineering and Engineering Research Institute, Chonnam National University, 300 Yongbong-Dong, 500-757, Gwangju, Republic of Korea. dmkim@chnnam.ac.kr
Doman
D
Kim
John F
JF
Robyt
So-Young
SY
Lee
Jin-Ha
JH
Lee
Young-Min
YM
Kim
D003911:Dextrans / Q000737:chemistry* / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D005964:Glucosyltransferases / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis / Q000187:drug effects; D007934:Leuconostoc / Q000201:enzymology*; D008970:Molecular Weight; D013395:Sucrose / Q000494:pharmacology*; D013696:Temperature
D003911:Dextrans; D013395:Sucrose; D005964:Glucosyltransferases; C020025:dextransucrase