PMID- 10441114
OWN - NLM
STAT- MEDLINE
DCOM- 19990908
LR  - 20061115
IS  - 0006-2960 (Print)
IS  - 0006-2960 (Linking)
VI  - 38
IP  - 32
DP  - 1999 Aug 10
TI  - Novel glycosylated forms of human plasma endostatin and circulating
      endostatin-related fragments of collagen XV.
PG  - 10217-24
AB  - Circulating elongated forms of the angiogenesis inhibitor and potential
      anti-cancer drug endostatin were isolated from human blood filtrate.
      Immunoreactive endostatin was identified by a polyclonal rabbit antiserum raised 
      against an N-terminal epitope of the polypeptide and purified by consecutive
      chromatographic steps and immunoblotting. N- and C-terminal sequence analyses of 
      the isolated molecules revealed different forms of endostatin starting with
      V(117)HLRPAR. lacking the last and final three residues of the noncollagenous
      domain 1 (NC-1) of collagen XVIII, respectively. These polypetides are found to
      be O-glycosylated at T(125) (residue 9) with a glycan structure of the mucin type
      consisting of galactose N-acetylgalactosamine and N-acetylneuraminic acid
      residues. Carbohydrate analyses were performed via the semiquantitative
      HPLC-electrospray ionization mass spectrometry (ESMS) technique after
      exoglycosidase hydrolysis. Circulating endostatins are present as
      sialoglycoprotein (22 000 and 21 841 Da +/- 0.02%) and asialoglycoprotein
      structures (21 710 and 21 549 Da +/- 0.02%), while the two completely
      deglycosylated forms are obtained only after enzymatic incubation. The described 
      glycosylated endostatins may represent intermediates in the proteolytic pathway
      of the NC-1 domain of collagen XVIII resulting in bioactive endostatins.
      Furthermore, immunoreactive endostatin-related C-terminal fragments of human
      collagen XV are found in the hemofiltrate. These polypeptides exhibit the
      N-terminal sequences P(66)HLLPPP. and Y(81)EKPALH. of the collagen XV NC-1
      domain. ESMS and immunoblotting analyses reveal three glycosylated polypeptides
      with a molecular mass ranging from 16 to 21 kDa. Due to the high degree of
      homology between collagen XV and collagen XVIII as well as their analoqous
      proteolytic processing, functional similarities of collagen XVIII- and XV-related
      fragments should be revealed in future experiments.
FAU - John, H
AU  - John H
AD  - Lower Saxony Institute for Peptide Research (IPF), Hannover, Germany.
FAU - Preissner, K T
AU  - Preissner KT
FAU - Forssmann, W G
AU  - Forssmann WG
FAU - Standker, L
AU  - Standker L
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - Biochemistry
JT  - Biochemistry
JID - 0370623
RN  - 0 (Collagen Type XVIII)
RN  - 0 (Endostatins)
RN  - 0 (Oligosaccharides)
RN  - 0 (Peptide Fragments)
RN  - 9007-34-5 (Collagen)
SB  - IM
MH  - Amino Acid Sequence
MH  - Animals
MH  - Blotting, Western
MH  - Collagen/*blood/*chemistry/isolation & purification
MH  - Collagen Type XVIII
MH  - Endostatins
MH  - Female
MH  - Glycosylation
MH  - Humans
MH  - Mass Spectrometry
MH  - Molecular Sequence Data
MH  - Oligosaccharides/analysis
MH  - Peptide Fragments/*blood/*chemistry/isolation & purification
MH  - Rabbits
EDAT- 1999/08/11 00:00
MHDA- 1999/08/11 00:01
CRDT- 1999/08/11 00:00
PHST- 1999/08/11 00:00 [pubmed]
PHST- 1999/08/11 00:01 [medline]
PHST- 1999/08/11 00:00 [entrez]
AID - 10.1021/bi990787+ [doi]
AID - bi990787+ [pii]
PST - ppublish
SO  - Biochemistry. 1999 Aug 10;38(32):10217-24. doi: 10.1021/bi990787+.