U.S. flagAn official website of the United States government
                    Here's how you know **Official websites use .gov**
                            
                            A **.gov** website belongs to an official government organization in the United States.
 **Secure .gov websites use HTTPS**
                            
                            A **lock** (                            
                              A locked padlock                                                      
                            
                            ) or **https://** means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.


Menu Agricultural Research Service
						
                    U.S. DEPARTMENT OF AGRICULTURE
 Produce Safety and Microbiology Research: Albany, CA
 close



    Research

                    Research Projects
                                    Publications
                                    Collaborations
                                    News
                People

                    Staff Listing
                                    CareersSearch small
                    Search
            
            ARS Home
                                About ARS
                                Contact Us




ARS Home Pacific West Area Albany, California Western Regional Research Center Produce Safety and Microbiology Research Research Publications at this Location





- ARS National Programs
- Search for a scientific manuscript
- Search for a research project
- ARS Software
- Programs and Projects
- Collaborations
- Subjects of Investigation
- Publications

Title:   Author  item
                                            Friedman, Mendelitem
                                            Levin, Carol
  Submitted to: Book Chapter
                                    Publication Type: Book / Chapter
                                    Publication Acceptance Date: 9/8/2010
                                    Publication  Date: 1/1/2012
                                    Citation: Friedman, M., Levin, C.E. 2012. Nutritional value of D-amino acids, D-peptides, and amino acid derivatives in mice. Polleioni & Servi, S., editors. Unnatural Amino Acids Methods and Protocols. New York Dordrecht Heidelberg London. Humana Press. Vol. 794, p. 337-356.Interpretive Summary: As part of an effort to develop a better understanding of the nutritional value and safety of novel amino acid derivatives (D-amino acids, cross-linked amino acids, oxidized amino acid, Maillard browning products) formed during food processing, we previously published a series of papers in the Journal of Nutrition and in Nutrition Reports International on a method to determine the nutritional value and potential toxicity of unnatural amino acids in mice. The bioassay uses an all-amino acid diet in which an essential amino acid is replaced by the unnatural amino acid. Mice provide a good in vivo model to study the nutritional utilization and biological effects of unnatural amino acids.  A major advantage of mouse bioassays is that they require about one-fifth of the test substance needed for rats and can be completed in 14 days.  The method can be used to determine the nutritional value and safety of hundreds of unnatural amino acids present in processed foods and synthesized by plants, bacteria, and animals. This paper was prepared in response to an invitation from Loredano Pollegioni and Stefano Servi, Editors of the widely circulated series of volumes entitled Methods in Molecular Biology, to contribute an experimental protocol to a forthcoming volume in this series entitled Unnatural Amino Acids. The research protocols are all peer-reviewed.  The updated description of the bioassay will facilitate its use by the scientific community.
                                Technical Abstract: This paper describes a method for determining the nutritional value of D-amino acids, D-peptides, and amino acid derivatives using a growth assay in mice fed a synthetic all-amino acid diet.  A large number of experiments were carried out in which a molar equivalent of the test compound replaced a nutritionally essential amino acid such as lysine (Lys), methionine (Met), phenylalanine (Phe), and tryptophan (Trp) as well as the semi-essential amino acids cysteine (Cys) and tyrosine (Tyr).  The results show wide-ranging variations in the biological utilization of test substances derived from Cys, histidine (His), isoleucine (Ile), Lys, Met, Trp, Tyr, and valine (Val).  The method is generally applicable to the determination of the biological utilization and safety of any amino acid derivative as a potential nutritional source of the corresponding L-amino acid.  Because the organism is forced to use the D-amino acid or amino acid derivative as the sole source of the essential or semi-essential amino acid being replaced, and because a free amino acid diet allows better control of composition, the use of all-amino-acid may be preferable to protein-based diets.


Return to top


Connect with ARS Sign up


ARS Home
                            USDA.gov
                            Plain Writing
                            Policies & Links
                            Civil Rights Statements
                            FOIA
                            Accessibility Statement
                            Privacy Policy
                            Non-Discrimination Statement
                            Quality of Information
                            USA.gov
                            WhiteHouse.gov