TY - JOUR
T1 - Head-to-tail polymerization of coagulin, a clottable protein of the horseshoe crab
AU - Kawasaki, Hiroko
AU - Nose, Takeru
AU - Muta, Tatsushi
AU - Iwanaga, Sadaaki
AU - Shimohigashi, Yasuyuki
AU - Kawabata, Shun Ichiro
N1 - Copyright:
Copyright 2007 Elsevier B.V., All rights reserved.
PY - 2000/11/10
Y1 - 2000/11/10
N2 - A clottable protein coagulogen of the horseshoe crab Tachypleus tridentatus is proteolytically converted into an insoluble coagulin gel through non-covalent self-polymerization. Here we identified binding sites for the polymerization. A tryptic fragment, derived from the coagulin polymer chemically cross-linked by a bifunctional cross-linker, was isolated. Amino acid sequence analysis indicated that the fragment consists of two peptides cross-linked between Lys85 and Lys156. The two lysine residues are oppositely located at the head and tail regions of the elongated molecule separated by a much greater distance than the length of the cross-linker, which suggests that the cross-linking occurs intermolecularly. Based on the x-ray structural analysis, exposure of a hydrophobic cove on the head in response to the release of peptide C has been postulated (Bergner, A., Oganessyan, V., Muta, T., Iwanaga, S., Typke, D., Huber, R., and Bode, W. (1996) EMBO J. 15, 6789-6797). An octapeptide containing Tyr136, which occupies the tail end of coagulin, was found to inhibit the polymerization. Replacement of Tyr136 of the peptide with Ala resulted in loss of the inhibitory activity. These results indicated that the polymerization of coagulin proceeds through the interaction between the newly exposed hydrophobic cove on the head and the wedge-shaped hydrophobic tail.
AB - A clottable protein coagulogen of the horseshoe crab Tachypleus tridentatus is proteolytically converted into an insoluble coagulin gel through non-covalent self-polymerization. Here we identified binding sites for the polymerization. A tryptic fragment, derived from the coagulin polymer chemically cross-linked by a bifunctional cross-linker, was isolated. Amino acid sequence analysis indicated that the fragment consists of two peptides cross-linked between Lys85 and Lys156. The two lysine residues are oppositely located at the head and tail regions of the elongated molecule separated by a much greater distance than the length of the cross-linker, which suggests that the cross-linking occurs intermolecularly. Based on the x-ray structural analysis, exposure of a hydrophobic cove on the head in response to the release of peptide C has been postulated (Bergner, A., Oganessyan, V., Muta, T., Iwanaga, S., Typke, D., Huber, R., and Bode, W. (1996) EMBO J. 15, 6789-6797). An octapeptide containing Tyr136, which occupies the tail end of coagulin, was found to inhibit the polymerization. Replacement of Tyr136 of the peptide with Ala resulted in loss of the inhibitory activity. These results indicated that the polymerization of coagulin proceeds through the interaction between the newly exposed hydrophobic cove on the head and the wedge-shaped hydrophobic tail.
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U2 - 10.1074/jbc.M006856200
DO - 10.1074/jbc.M006856200
M3 - Article
C2 - 10948203
AN - SCOPUS:0034634579
VL - 275
SP - 35297
EP - 35301
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 45
ER -