MAIZE RIBOSOME-INACTIVATING PROTEIN (B-32) - HOMOLOGS IN RELATED SPECIES, EFFECTS ON MAIZE RIBOSOMES, AND MODULATION OF ACTIVITY BY PRO-PEPTIDE DELETIONS
UNSPECIFIED. (1995) MAIZE RIBOSOME-INACTIVATING PROTEIN (B-32) - HOMOLOGS IN RELATED SPECIES, EFFECTS ON MAIZE RIBOSOMES, AND MODULATION OF ACTIVITY BY PRO-PEPTIDE DELETIONS. PLANT PHYSIOLOGY, 107 (4). pp. 1323-1332. ISSN 0032-0889Full text not available from this repository.
The ribosome-inactivating protein (RIP) from maize (Zea mays L.) is unusual in that it is produced in the endosperm as an inactive pro-form, also known as b-32, which can be converted by limited proteolysis to a two-chain active form, alpha beta RIP. Immunological analysis of seed extracts from a variety of species related to maize showed that pro/alpha beta forms of RIP are not unique to maize but are also found in other members of the Panicoideae, including Tripsacum and sorghum. Ribosomes isolated from maize were quite resistant to both purified pro- and alpha beta maize RIPs, whereas they were highly susceptible to the RIP from pokeweed. This suggests that the production of an inactive pro-RIP is not a mechanism to protect the plant's own ribosomes from deleterious action of the alpha beta RIP. RIP derivatives with various pro-segments removed were expressed at high levels in Escherichia coli. Measurement of their activity before and after treatment with subtilisin Carlsberg clearly identified the 25-amino acid intradomain insertion, rather than the N- or C-terminal extensions, as the major element responsible for suppression of enzymatic activity. A RIP with all three processed regions deleted had activity close to that of the native alpha beta form.
|Item Type:||Journal Article|
|Subjects:||S Agriculture > SB Plant culture|
|Journal or Publication Title:||PLANT PHYSIOLOGY|
|Publisher:||AMER SOC PLANT PHYSIOLOGISTS|
|Number of Pages:||10|
|Page Range:||pp. 1323-1332|
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