Title : Posttranslationally processed forms of the human chemokine
HCC-1
Abstract :
- HCC-1 is the only CC-chemokine known so far which circulates in nanomolar concentrations in human plasma
- Its physiological function is not well defined
- Posttranslational processing of HCC-1 was shown to modulate its biological properties
- In this study several different processed forms of HCC-1 were isolated
- Western blot analysis of human plasma extracts revealed a HCC-1 immunoreactive double band at 8-10 kDa indicating the presence of two distinct HCC-1 peptides
- These peptides were isolated from a peptide library of human blood filtrate and represent predominantly HCC-1 ( 1-74 ) and glycosylated HCC-1 ( 1-74 )
- Glycosylated HCC-1 exhibits a molecular mass of 9621 Da due to O-glycosylation at position 7 ( Ser-7 ) with two N-acetylneuraminic acids and the disaccharide N-acetylgalactosamine galactose.
- Furthermore N-terminally truncated HCC-1 ( 3-74 ) and HCC-1 ( 4-74 ) were identified in the peptide library
- In hemofiltrate approximately 3% of total HCC-1 represents HCC-1 ( 3-74 ) and approximately 1% represents HCC-1 ( 4-74 ) whereas the major products are nonglycosylated HCC-1 ( 1-74 ) and glycosylated HCC-1 ( 1-74 )
- Our data imply that HCC-1 ( 1-74 ), HCC-1 ( 3-74 ), HCC-1 ( 4-74 ) and glycosylated HCC-1 ( 1-74 ) circulate in human blood
- The N-terminal processing and modification of HCC-1 might be of importance in displaying its full biological activity