Gonçalves Fernando, Heyraud Alain, de Pinho Maria Norberta, Rinaudo Marguerite
Departamento de Engenharia Química, Instituto Superior Técnico, Avenida Rovisco Pais, 1049-001 Lisboa, Portugal.
J Agric Food Chem. 2002 Oct 9;50(21):6097-101. doi: 10.1021/jf0202741.
Mannoproteins, Saccharomyces cerevisiae yeast polysaccharides, play a major role in wine processing and characteristics. A systematic characterization of these polymers in terms of chemical composition and molecular structure is addressed in this study. Mannoproteins were isolated from white wine through a sequence of operations that consisted of nanofiltration for concentration of macromolecules, polysaccharide precipitation with ethanol, and affinity chromatography on concanavalin A. The whole wine mannoproteins present a very broad molecular mass distribution with several populations. Two major populations with very different compositions were separated by size exclusion chromatography. The mannoproteins with higher molecular mass are a mannose homopolymer containing 10.3% protein. The mannoproteins with lower molecular mass consisted of 87.5% of mannose and some other residues and a protein content of 2.5%. The highest molecular weight mannoprotein structure was examined by (1)H and (13)C NMR spectroscopic techniques such as 1-D TOCSY, 2-D COSY, and 2-D HMQC.
甘露糖蛋白，即酿酒酵母酵母多糖，在葡萄酒酿造过程及葡萄酒特性方面发挥着重要作用。本研究对这些聚合物的化学组成和分子结构进行了系统表征。通过一系列操作从白葡萄酒中分离出甘露糖蛋白，这些操作包括用于大分子浓缩的纳滤、用乙醇进行多糖沉淀以及在伴刀豆球蛋白A上进行亲和色谱。整个葡萄酒中的甘露糖蛋白呈现出非常宽泛的分子量分布，存在多个群体。通过尺寸排阻色谱分离出了两个组成差异很大的主要群体。分子量较高的甘露糖蛋白是一种含10.3%蛋白质的甘露糖均聚物。分子量较低的甘露糖蛋白由87.5%的甘露糖和一些其他残基以及2.5%的蛋白质含量组成。通过一维全相关谱（1-D TOCSY）、二维同核化学位移相关谱（2-D COSY）和二维异核多量子相干谱（2-D HMQC）等氢谱（1H）和碳谱（13C）核磁共振光谱技术对分子量最高的甘露糖蛋白结构进行了研究。
