PMID- 9692908
OWN - NLM
STAT- MEDLINE
DCOM- 19980824
LR  - 20190620
IS  - 0014-2956 (Print)
IS  - 0014-2956 (Linking)
VI  - 255
IP  - 1
DP  - 1998 Jul 1
TI  - Disulphide bonds assignment in the inter-alpha-inhibitor heavy chains--structural 
      and functional implications.
PG  - 107-15
AB  - Human inter-alpha-inhibitor (IalphaI) is a plasma serine-proteinase inhibitor. It 
      consists of three polypeptide chains covalently linked by a glycosaminoglycan: a 
      light one named bikunin, carrying the antiproteinase activity and two heavy 
      chains H1 and H2. The amino acid sequences of these heavy chains are highly 
      similar; however when IalphaI is digested by neutrophil proteinases, their 
      proteolytic susceptibility strongly differs [Balduyck, M., Piva, F., Mizon, C., 
      Maes, P., Malki, N., Gressier, B., Michalski, C. & Mizon, J. (1993) Human 
      leucocyte elastase (HLE) preferentially cleaves the heavy chain H2 of 
      inter-alpha-trypsin inhibitor (ITI), Biol. Chem. Hoppe-Seyler 374, 895-901]. We 
      mapped the disulphide topology of the IalphaI heavy chains in order to 
      investigate whether or not disulphide bonds might be responsible for their 
      differential susceptibility to proteolysis. Using amino acid sequencing and mass 
      spectrometry analysis, we demonstrate that the H1 heavy chain contains one free 
      thiol group and two disulphide bridges of which one links two largely spaced 
      cysteine residues (Cys239 and Cys511). Thus H1 is clearly different from H2 which 
      contains two disulphide bonds between closely located cysteine residues. However, 
      using immunoprint analysis, we show that, when IalphaI is subjected to a limited 
      digestion by Staphylococcus aureus V-8 proteinase, the two polypeptide chains are 
      similarly susceptible to proteolysis. This enzyme preferentially cleaves the 
      IalphaI heavy chains from their N-terminal extremity. These results are 
      consistent with the circular dichroism (CD) analysis, suggesting that the 
      conformation of the polypeptide backbone of H1 is not very different from that of 
      H2, with calculated alpha-helicities of 24% and 28%, respectively. The CD 
      measurements reveal that the aromatic amino acids of H1 and H2 are in a different 
      asymmetrical environment. Inside the IalphaI molecule, the heavy chains are 
      linked to the glycosaminoglycan chain via their C-terminal aspartic acid residue. 
      Thus we suggest that the affinity of cationic neutrophil proteinases for the 
      anionic glycosaminoglycan is responsible for the cleavage of the heavy chains 
      (mainly H2) near their C-terminal end and the high susceptibility of IalphaI to 
      these proteinases.
FAU - Flahaut, C
AU  - Flahaut C
AD  - Laboratoire de Biochimie, Faculte de Pharmacie, Lille, France.
FAU - Mizon, C
AU  - Mizon C
FAU - Aumercier-Maes, P
AU  - Aumercier-Maes P
FAU - Colson, P
AU  - Colson P
FAU - Bailly, C
AU  - Bailly C
FAU - Sautiere, P
AU  - Sautiere P
FAU - Mizon, J
AU  - Mizon J
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - England
TA  - Eur J Biochem
JT  - European journal of biochemistry
JID - 0107600
RN  - 0 (Alpha-Globulins)
RN  - 0 (Blood Proteins)
RN  - 0 (Disulfides)
RN  - 0 (Peptide Fragments)
RN  - 0 (Serine Proteinase Inhibitors)
RN  - 39346-44-6 (inter-alpha-inhibitor)
RN  - EC 3.4.- (Cathepsins)
RN  - EC 3.4.- (Endopeptidases)
RN  - EC 3.4.21.- (Serine Endopeptidases)
RN  - EC 3.4.21.19 (glutamyl endopeptidase)
RN  - EC 3.4.21.20 (CTSG protein, human)
RN  - EC 3.4.21.20 (Cathepsin G)
RN  - EC 3.4.21.37 (Leukocyte Elastase)
RN  - EC 3.4.24.- (Metalloendopeptidases)
RN  - EC 3.4.24.20 (peptidyl-Lys metalloendopeptidase)
RN  - OS382OHJ8P (Cyanogen Bromide)
SB  - IM
MH  - Alpha-Globulins/*chemistry/metabolism
MH  - Amino Acid Sequence
MH  - Blood Proteins/*chemistry/metabolism
MH  - Cathepsin G
MH  - Cathepsins/metabolism
MH  - Circular Dichroism
MH  - Cyanogen Bromide
MH  - Disulfides/*chemistry/metabolism
MH  - Endopeptidases/*metabolism
MH  - Humans
MH  - Leukocyte Elastase/metabolism
MH  - Metalloendopeptidases/metabolism
MH  - Molecular Sequence Data
MH  - Peptide Fragments/chemistry
MH  - Sequence Analysis
MH  - Serine Endopeptidases/metabolism
MH  - Serine Proteinase Inhibitors/*chemistry/metabolism
EDAT- 1998/08/06 00:00
MHDA- 1998/08/06 00:01
CRDT- 1998/08/06 00:00
PHST- 1998/08/06 00:00 [pubmed]
PHST- 1998/08/06 00:01 [medline]
PHST- 1998/08/06 00:00 [entrez]
AID - 10.1046/j.1432-1327.1998.2550107.x [doi]
PST - ppublish
SO  - Eur J Biochem. 1998 Jul 1;255(1):107-15. doi: 10.1046/j.1432-1327.1998.2550107.x.