skip to main content


Search for: All records

Creators/Authors contains: "Goonatilleke, Elisha"

Note: When clicking on a Digital Object Identifier (DOI) number, you will be taken to an external site maintained by the publisher. Some full text articles may not yet be available without a charge during the embargo (administrative interval).
What is a DOI Number?

Some links on this page may take you to non-federal websites. Their policies may differ from this site.

  1. Scope

    The use of human milk products is increasing for high‐risk infants. Human milk contains endogenous enzymes that comprise a dynamic proteolytic system, yet biological properties of these enzymes and their activities in response to variations including pH within infants are unclear. Human milk has a neutral pH around 7, while infant gastric pH varies from 2 to 6 depending on individual conditions. This study is designed to determine the specificity of enzyme–substrate interactions in human milk as a function of pH.

    Methods and results

    Endogenous proteolysis is characterized by incubating freshly expressed human milk at physiologically relevant pH ranging from 2 to 7 without the addition of exogenous enzymes. Results show that the effects of pH on endogenous proteolysis in human milk are protein‐specific. Further, specific interactions between cathepsin D and α‐lactalbumin are confirmed. The endogenous enzyme cathepsin D in human milk cleaves α‐lactalbumin as the milk pH shifts from 7 to 3.

    Conclusions

    This study documents that selective proteolysis activated by pH shift is a mechanism for dynamic interactions between human milk and the infant. Controlled proteolysis can guide the use of human milk products based on individual circumstance.

     
    more » « less