Abstract
The composition of subunits of the intestinal brush border has been studied. Fractions obtained after Tris disruption and subsequent density-gradient centrifugation were analyzed for their enzymic and chemical content. These fractions include a major membrane component, a minor membrane component, microvillus cores and two that are unidentified. The major membrane fraction contains all of the alkaline phosphatase, maltase, invertase, lactase, isomaltase, trehalase and leucyl naphthylamide hydrolase activities of the brush border. It also contains ATPase. A different ATPase activity is found in one of the morphologically identified fractions. It appears to be associated with a fibrillar material which can be formed from this fraction by appropriate treatment. Lactase activity is occasionally found to be differently distributed from the other disaccharidases; i.e., an appreciable amount appears in the minor membrane component. No enzymatic activities were found in the fraction composed of microvillus cores. All fractions were analyzed for protein, carbohydrate, cholesterol, phospholipid and DNA. Cholesterol to phospholipid ratio of 1.1 was found in the major membrane fraction.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
