발아초기의 콩 부위별 Lactate Dehydrogenase 활성변화 및 효소성질 비교

Comparision of the Activity and Characteristics of Lactate Dehydrogenase Isolated from Different Parts of Soybean Seedling

발아초기(發芽初期)에 콩(대두(大豆))의 부위별(部位別)로 Lactate dehydrogenase(LDH)의 Isozyme 존재가능성(存在可能性)을 조사(調査)하기 위한 기초적(基礎的)인 연구(硏究)가 수행(遂行)되었다. 발아가 진행(進行)됨에 따라 자엽부위의 효소활성변화(酵素活性變化)에는 큰 유의성이 나타나지 않았으나, 배축이나 뿌리 부위(部位)에서는 감소하는 경향을 보였으며 $4{\sim}7^{\circ}C$에서 배축이나 뿌리로부터 얻은 LDH는 자엽에서 얻은 LDH에 비(比)해 불안정(不安定)했다. 전기영동상의 Rm value가 자엽으로부터 얻은 효소(酵素)에서는 0.25인데 비하여, 배축으로 부터 분리된 LDH는 0.29였다. 배축이나 뿌리로 부터 분리된 LDH는 Biphasic으로 0.45mM과 0.014mM의 두 km값을 보이고 자엽부위에서는 0.45mM 값만 관찰할 수 있었다. 이상의 결과는 자엽부위의 LDH와는 다른 성질(性質)을 가진 LDH가 배축이나 뿌리부위(部位)에 존재(存在)할 가능성(可能性)을 보여주고 있다.

The change of lactate dehydrogenase(LDH) activity and the possibility of the existence of LDH. isozyme were examined with different parts of soybean sprout. The enzyme activity was little changed in cotyledons throughout the early stagy of germination. However, hypocotyls and roots showed the continuous decline of the enzyme activity since the radicle emerged from seeds. It was found that LDH from hypocotyls. and roots was unstable as compared with LDH from cotyledons, even at low temperature. The enzyme from hypocotyls and roots was not purified with a good yield when the purification procedure developed for LDH from cotyledons. was employed. LDH from hypocotyls and roots has the Rm value of 0.29, and 0.25 from cotyledons. The apparent Km value for LDH from cotyledons was 0.45mM with sodium pyruvate, while crude homogenate of hypocotyls or roots showed biphasic phenomenon with two Km values 0.014 and 0.45mM. The results indicate the possibility that crude homogenate of hypocotyls or roots may contain a different LDH isozyme from the LDH of soybean reported previously.