Abstract: 【Objective】 In order to provide the scientific basis for processing and utilization of mung bean protein, the dynamic changes of mung bean isolated protein, albumin, globulin, gluten and gliadin in different germination stages were investigated.【Method】The isolated protein of mung bean were extracted by isoelectric point precipitation method, and the albumin, gluten, globulin and gliadin of mung bean were prepared according to Osborne classification. The content of each kind of proteins and the activity of protease were determined in different germination period. The changes of composition and quantity of protein subunit before and after germination were further analyzed by SDS-PAGE electrophoresis.【Result】With the extension of germination time, the contents of mung bean isolated protein increased first and then decreased. The Mung bean isolated protein was increased by 9.4% compared to non-germinated mung bean. The Mung bean albumin content was decreased after the germination, which the minimum value was 20.47 mg·g^-1. The globulin content was increased first and then decreased with the increasing of germination time, with the minimum was observed at 0 h and the highest at 48 h after germination. However, the gliadin content was not influenced by the germination. There was no significant difference in the gluten content of mung bean between the 12-36 h and 48-72 h germination, but the content is still higher than non-germinated seed. Mung bean protease activity increased within 36 h germination, and began to decline at 72 h. Analysis of SDS-PAGE electrophoresis and optical density scanning results showed that there were 7 bands (Ⅰ-Ⅶ) in the mung bean isolated protein, and the relative content of each band decreased continuously. After the germination, the molecular weight of 25 kD to 66 kD proteins gradually decreased. The content of 18 kD and 25 kD isolated proteins increased within 72 h germination, and almost only remained Ⅳ after 96 h of germination. Mung bean albumin mainly consisted of four bands (Ⅰ-Ⅳ) with molecular weights of 61.56, 48.99, 29.88 and 20.42 kD, respectively. During the germination process, the relative content of Band I decreased from 18.4% at 0 h to 16.4% at 60 h, and disappeared at 72 h after germination. Although the Band II existed during the whole germination, the relative content of Band II was decreased continuously from 51.1% to 27.0%. Bands Ⅲ and Ⅳ decreased continuously with the germination, and disappeared after 72h of germination. What’s more, the relative contents of subunit bands with a molecular weight of 18-25 kD increased at 24-60 h and disappeared after 72 h of germination. Mung bean globulin mainly consists of five bands (Ⅰ-Ⅴ) with molecular weights of 66, 61, 50, 32 and 26 kD, respectively. The relative content of subunit bands I and II were disappeared after 96 h of germination. While the relative content of band Ⅲ increased gradually from 34.4% to 41.8% during 0 to 60 h of early stage of germination. Then the band Ⅲ content decreased rapidly after 72 h of germination and measured only 10.8% at 96 h. In the meantime, the relative contents of subunit Band Ⅳ and Ⅴ was not observed after 84 h germination. Subunit bands with a molecular weight of 18-25 kD increased during 24 to 60 h of germination, and then degraded or even disappeared with the germination process.【Conclusion】Appropriate germination not only increase the content of mung bean proteins and promote the hydrolysis of macromolecular subunits, but also facilitates the formation of small molecule subunits or polypeptides.

Key words: mung bean, germination, protein component, subunit