Title : The structure of recombinant human carboxy-terminal-truncated macrophage
colony-stimulating factor derived from mammalian cells
Abstract :
- The structure of recombinant human carboxy-terminal-truncated macrophage colony-stimulating factor expressed in CHO cells was investigated
- The bioactive protein ([-32-153] M-CSF ), expressed from a nucleotide sequence that encoded a signal peptide of 32 amino acids and N-terminal amino acids numbers 1-153, was heterogeneous in terms of molecular mass, as analyzed by SDS-PAGE, because of the presence of N-linked sugar moieties
- The primary structure of the polypeptide was determined by sequence analysis and amino acid analysis of the fragments obtained from lysylendopeptidase digests of reduced and alkylated M-CSF , and from pepsin digests of the intact molecule
- A sugar chain was located only at Asn-122 of the two putative sites of N-glycosylation that were present per subunit
- The homodimeric structure appeared to have seven disulfide bonds, formed by inter- or intra-molecular linkages, since there were no free thiol groups in the molecule
- The assignment of disulfide bonds by sequence analysis using peptide fragments indicated the combinations of Cys7-Cys90, Cys48-Cys139, and Cys102-Cys146
- Gel-filtration analysis of Ser31 [-32-153] M-CSF , in which the remaining Cys31 was replaced by Ser and which was expressed in COS cells, suggested that the mutein existed as a monomer
- Our study shows that the disulfide-bond pairings of [-32-153] M-CSF that is expressed and post-translationally modified in mammalian cells are identical to those of Escherichia coli-derived [3-153] M-CSF with only one intermolecular disulfide bond, namely, Cys31-Cys31
Output (sent_index, trigger,
protein,
sugar,
site):
- 4. Asn-122, , -, A sugar chain, Asn-122
- 4. N-glycosylation, , -, -, sites
- 4. located, , -, A sugar chain, Asn-122
Output(Part-Of) (sent_index,
protein,
site):
*Output_Site_Fusion* (sent_index,
protein,
sugar,
site):
- 4. colony-stimulating factor, A sugar chain, Asn-122