哺乳期南极毛皮海狮（食蟹海豹）的肠道乳糖酶及其他双糖酶活性

Intestinal lactase and other disaccharidase activities of a suckling crabeater seal (Lobodon carcinophagus).

Crisp E A, Messer M, Shaughnessy P D

Department of Biochemistry, University of Sydney, N.S.W., Australia.

Comp Biochem Physiol B. 1988;90(2):371-4. doi: 10.1016/0305-0491(88)90089-2.

Abstract

The intestinal disaccharidase activities of a suckling crabeater seal were investigated. 2. Lactase, maltase, isomaltase and cellobiase activities were readily detected but trehalase and sucrase activities were absent. 3. The intestinal homogenates were separated into a soluble (S2) fraction and a particulate brush border (P2) fraction. The lactase activities of the two fractions had different properties corresponding to those of an acid and a neutral beta-galactosidase respectively. Approximately two-thirds of the total lactase activity measured at pH 6.0 was due to the acid beta-galactosidase. 4. The isomaltase and cellobiase activities were found almost exclusively in the particulate fractions but about one third of the maltase activity was in the S2 fraction. This soluble maltase activity appeared to be due to an acid maltase.

摘要

对一只哺乳期食蟹海豹的肠道双糖酶活性进行了研究。2. 乳糖酶、麦芽糖酶、异麦芽糖酶和纤维二糖酶的活性很容易检测到，但海藻糖酶和蔗糖酶活性未检测到。3. 将肠道匀浆分离成可溶性（S2）部分和颗粒状刷状缘（P2）部分。这两个部分的乳糖酶活性具有不同特性，分别对应于酸性和中性β-半乳糖苷酶的特性。在pH 6.0时测得的总乳糖酶活性中，约三分之二归因于酸性β-半乳糖苷酶。4. 异麦芽糖酶和纤维二糖酶活性几乎完全存在于颗粒部分，但约三分之一的麦芽糖酶活性存在于S2部分。这种可溶性麦芽糖酶活性似乎归因于酸性麦芽糖酶。