NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Utilization of [14C]phenylalanine derived from arylphorin or free amino acid in Manduca sexta pharate adultsThe role of arylphorin as a storage protein was studied using 14C-arylphorin. 14C-arylphorin was produced optimally by incubating one-half fat body from Manduca sexta fifth instar larvae at 22 degrees C for 24 h, in 1 ml of medium containing amino acids at 25% of their physiological concentration with [U-14C]-phenylalanine (phe) provided initially without nonlabeled phenylalanine. Nonlabeled phe was provided after 1 h at 16% of its physiological concentration. The specific activity of 14C-arylphorin produced in vitro was 30 times greater than that generated in vivo. Injection of 14C-arylphorin into pharate adults was used to study the distribution of 14C-phe derived from this protein into 14CO2 and tissues for comparison with injection of free 14C-phe during the middle (days 6 to 12 pharate adult) and late (days 12 to 17 pharate adult) stages of adult development. Appearance of 14CO2 from 14C-arylphorin as compared to 14C-phenylalanine showed a slower time course during both the middle and late stages of development, in keeping with the time needed for degradation of the protein. In accord with faster phe turnover near the end of adult development, total 14CO2 production was greater and the retention of 14C in hemolymph and fat body was less compared to the middle stage of development regardless of whether 14C-arylphorin or 14C-phe was injected. In the middle stage of development, the appearance of 14C in the cuticle and head parts was greater, whereas incorporation into abdomen and thorax was less than during the late stage of development. Since the pattern of 14C distribution from 14C-arylphorin and 14C-phe was similar, one major function of arylphorin must be as a storage protein replenishing the supply of free amino acids used for synthesis of adult tissues. These results also suggest a limited contribution of M. sexta arylphorin to formation of the cuticle subsequent to day-6 pharate adult.
Document ID
20040112229
Acquisition Source
Headquarters
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Wu, M.
(The University of Arizona Tucson, United States)
Tischler, M. E.
Date Acquired
August 21, 2013
Publication Date
January 1, 1995
Publication Information
Publication: Archives of insect biochemistry and physiology
Volume: 28
Issue: 3
ISSN: 0739-4462
Subject Category
Life Sciences (General)
Funding Number(s)
CONTRACT_GRANT: NAGW-3197
CONTRACT_GRANT: DCB-8712458
CONTRACT_GRANT: DIR8-720082
Distribution Limits
Public
Copyright
Other
Keywords
Non-NASA Center
NASA Program Space Biology
NASA Discipline Number 40-20
NASA Discipline Developmental Biology

Available Downloads

There are no available downloads for this record.
No Preview Available