Nakano Takuo, Betti Mirko
Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta T6G 2P5, Canada.
J Dairy Res. 2022 Apr 7:1-4. doi: 10.1017/S0022029922000280.
Bovine κ-casein glycomacropeptide (GMP) is a sialic acid containing glycopeptide, which is considered as a health promoting compound found in cheese whey. The study described in this research communication was undertaken to determine whether GMP with undetectable level of contaminating protein or phenylalanine can be isolated from bovine whey fraction using batch anion exchange technique with chitin as an adsorbent. A soluble whey fraction (SWF) prepared from 1 g whey protein isolate (WPI) was mixed with a slurry of 1 g chitin, and the mixture was incubated at pH 3.0. After incubation, the mixture was filtered, and the residue obtained (containing chitin-GMP complex) was washed with water and eluted stepwise with 0.5 M NaCl and 2.0 M NaCl. Most of GMP (corresponding to 75.8% of total sialic acid recovered) was eluted with 0.5 M NaCl. The recovered GMP accounted for 5.4% dry weight of WPI (or 18.9% dry weight of SWF). Amino acid analysis showed that there was no detectable level of contaminating amino acids including phenylalanine, histidine, arginine and tyrosine in the GMP fraction. It was concluded that the batch anion exchange method with chitin developed in this study can be used for the isolation of high purity GMP from bovine SWF.
牛κ-酪蛋白糖巨肽（GMP）是一种含唾液酸的糖肽，被认为是奶酪乳清中一种具有促进健康作用的化合物。本研究通讯中描述的研究旨在确定是否可以使用以几丁质为吸附剂的分批阴离子交换技术，从牛乳清组分中分离出污染蛋白或苯丙氨酸含量不可检测的GMP。将由1 g乳清蛋白分离物（WPI）制备的可溶性乳清组分（SWF）与1 g几丁质的浆液混合，并将混合物在pH 3.0下孵育。孵育后，将混合物过滤，所得残渣（含几丁质-GMP复合物）用水洗涤，并用0.5 M NaCl和2.0 M NaCl逐步洗脱。大部分GMP（相当于回收的总唾液酸的75.8%）用0.5 M NaCl洗脱。回收的GMP占WPI干重的5.4%（或SWF干重的18.9%）。氨基酸分析表明，GMP组分中未检测到包括苯丙氨酸、组氨酸、精氨酸和酪氨酸在内的污染氨基酸。得出的结论是，本研究中开发的以几丁质为基础的分批阴离子交换方法可用于从牛SWF中分离高纯度的GMP。
