Warchol M, Perrin S, Grill J-P, Schneider F
Laboratoire de Biochimie des Bactéries Gram +, Université Henri Poincaré-Nancy I, Faculté des Sciences et Techniques, Vandoeuvre-lès-Nancy Cedex, France.
Lett Appl Microbiol. 2002;35(6):462-7. doi: 10.1046/j.1472-765x.2002.01224.x.
To characterize the beta-fructofuranosidase of Bifidobacterium infantis ATCC 15697 and to compare it with other bacterial beta-fructofuranosidases.
The beta-fructofuranosidase of B. infantis ATCC 15697 was purified 46.8 times over the crude extract by anion exchange chromatography, ultrafiltration and gel filtration. The sequence of 15 amino acid residues of the NH2 terminal was determined. This enzyme was a monomeric protein (Mr 70 kDa) with beta-fructofuranosidase and invertase activities. The isoelectric point was pH 4.3, the optimum pH 6.0 and pKas (4.5 and 7.2) of two active groups were obtained. The activities were inhibited by Hg2+ and p-chloromercuribenzoic acid (pCMB). The optimal temperature was 37 degrees C and activities were unstable at 55 degrees C. beta-fructofuranosidase activity was more efficient than that of invertase with Vm/Km ratios of 0.65 and 0.025 x 10-3 l min(-1) mg(-1), respectively. The enzyme catalyses the hydrolysis of fructo-oligosaccharides, sucrose and inulin at relative velocities of 100, 10 and 6, respectively.
The enzyme of B. infantis ATCC 15697 is an exo-inulinase which has beta-fructofuranosidase and invertase activities. This protein was different from the beta-fructofuranosidase of another strain of B. infantis (B. infantis JCM no. 7007).
A better knowledge of bacterial beta-fructofuranosidases, especially from bifidobacteria, has been gained.
对婴儿双歧杆菌ATCC 15697的β-呋喃果糖苷酶进行特性分析，并与其他细菌的β-呋喃果糖苷酶进行比较。
通过阴离子交换色谱、超滤和凝胶过滤，将婴儿双歧杆菌ATCC 15697的β-呋喃果糖苷酶从粗提物中纯化了46.8倍。测定了氨基末端15个氨基酸残基的序列。该酶是一种具有β-呋喃果糖苷酶和转化酶活性的单体蛋白（分子量70 kDa）。等电点为pH 4.3，获得了最佳pH 6.0以及两个活性基团的pKa值（4.5和7.2）。其活性受到Hg2+和对氯汞苯甲酸（pCMB）的抑制。最佳温度为37℃，在55℃时活性不稳定。β-呋喃果糖苷酶活性比转化酶活性更高效，Vm/Km比值分别为0.65和0.025×10-3 l min-1 mg-1。该酶催化低聚果糖、蔗糖和菊粉水解的相对速度分别为100、10和6。
婴儿双歧杆菌ATCC 15697的酶是一种具有β-呋喃果糖苷酶和转化酶活性的外切菊粉酶。这种蛋白质与另一株婴儿双歧杆菌（婴儿双歧杆菌JCM no. 7007）的β-呋喃果糖苷酶不同。
对细菌β-呋喃果糖苷酶，尤其是双歧杆菌的β-呋喃果糖苷酶有了更深入的了解。
