Location of cysteine residues and the biological activities of the fluorescence­ labeled cinnamomin

Title:Location of cysteine residues and the biological activities of the fluorescence­ labeled cinnamomin

Volume: 7 Issue: 4

Author(s): Liang Xie, Fa-Jian Hou, Wang-Yi Liu*En-Duo Wang

Affiliation:

• Laboratory of Ribosome Research, Academia Sinica. 320 Yue-yang Road, Shanghai 200031, China

Abstract: Cinnamomin is a type II ribosome-inactivating protein (RIP) isolated from the seeds of Cinnamomum camphora. It is composed of two glycopeptide chains (A- and B-chain). The A-chain exhibits RNA N­ glycosidase activity, depurinating an adenosine from the largest ribosomal RNA and thus inhibiting protein synthesis. The B-chain is a lectin, recognizing the galactose-containing receptor on the cell surface and facilitating entry of the A-chain into the cell. A total of ten cysteines were titrated with DTNB in the cinnamomin molecule, one in the A-chain and the other in the B-chain. All the ·cysteines existed in the disulfide bond form in cinnamomin, which probably accounted for its high structural stability. On the other hand, the sugar chains of cinnamomin were oxidized with periodate and then fluorescence-labeled with FTSC. Both the RNA N-glycosidase activity of its A-chain and the lectin activity of its B-chain decreased three fold after fluorescence-labeling.

Cite this article as:

Xie Liang, Hou Fa-Jian, Liu Wang-Yi*, Wang En-Duo, Location of cysteine residues and the biological activities of the fluorescence­ labeled cinnamomin, Protein & Peptide Letters 2000; 7 (4) . https://dx.doi.org/10.2174/092986650704221207123809

DOI https://dx.doi.org/10.2174/092986650704221207123809	Print ISSN 0929-8665
Publisher Name Bentham Science Publisher	Online ISSN 1875-5305