Talamond Pascale, Noirot Michel, de Kochko Alexandre
Institut de Recherche pour le Développement, UMR 141, 911 av. d'Agropolis, BP 64501, 34394 Montpellier, Cedex 5, France.
J Chromatogr B Analyt Technol Biomed Life Sci. 2006 Apr 13;834(1-2):42-7. doi: 10.1016/j.jchromb.2006.02.005. Epub 2006 Mar 13.
The action pattern of Lactobacillus fermentum alpha-amylase (FERMENTA) was examined using a series of maltooligosaccharides (G2-G7) as substrates. Structurally, this enzyme has a molecular mass (106 kDa) almost twofold higher than alpha-amylases from mammalians and cereals. The product pattern was investigated through an analysis of products and substrates using HPAEC with pulsed amperometric detection. FERMENTA was consistent with an endo-type of amylase. The bond cleavage frequencies were studied using maltooligosaccharides of various chain lengths as substrate, i.e. maltose up to maltoheptaose and DP 4900-amylose catalyzed by FERMENTA. The catalytic efficiency (k(cat)/K(m)) increased with chain length from maltose (8.7 x 10(4) M(-1) s(-1)) up to amylose (1 x10(9) M(-1) s(-1)). These action pattern results revealed that FERMENTA can readily cleave the third linkage from the reducing end of the maltooligosaccharides (G5-G7).
以一系列麦芽寡糖（G2 - G7）为底物，对发酵乳杆菌α - 淀粉酶（FERMENTA）的作用模式进行了研究。从结构上看，这种酶的分子量（106 kDa）几乎是哺乳动物和谷物来源的α - 淀粉酶的两倍。通过使用配备脉冲安培检测的高效阴离子交换色谱（HPAEC）分析产物和底物，研究了产物模式。FERMENTA符合内切型淀粉酶。以不同链长的麦芽寡糖作为底物，即从麦芽糖到麦芽七糖以及由FERMENTA催化的DP 4900 - 直链淀粉，研究了键断裂频率。催化效率（k(cat)/K(m)）随着链长从麦芽糖（8.7×10⁴ M⁻¹ s⁻¹）增加到直链淀粉（1×10⁹ M⁻¹ s⁻¹）而提高。这些作用模式结果表明，FERMENTA能够轻易地从麦芽寡糖（G5 - G7）的还原端切割第三个键。
