Variegin, a novel fast and tight binding thrombin inhibitor from the tropical bont tick.

Tick saliva contains potent antihemostatic molecules that help ticks obtain their enormous blood meal during prolonged feeding. We isolated thrombin inhibitors present in the salivary gland extract from partially fed female Amblyomma variegatum, the tropical bont tick, and characterized the most pot...

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Main Authors: Koh, C, Kazimirova, M, Trimnell, A, Takac, P, Labuda, M, Nuttall, P, Kini, R
Format: Journal article
Language:English
Published: 2007
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author Koh, C
Kazimirova, M
Trimnell, A
Takac, P
Labuda, M
Nuttall, P
Kini, R
author_facet Koh, C
Kazimirova, M
Trimnell, A
Takac, P
Labuda, M
Nuttall, P
Kini, R
author_sort Koh, C
collection OXFORD
description Tick saliva contains potent antihemostatic molecules that help ticks obtain their enormous blood meal during prolonged feeding. We isolated thrombin inhibitors present in the salivary gland extract from partially fed female Amblyomma variegatum, the tropical bont tick, and characterized the most potent, variegin, one of the smallest (32 residues) thrombin inhibitors found in nature. Full-length variegin and two truncated variants were chemically synthesized. Despite its small size and flexible structure, variegin binds thrombin with strong affinity (K(i) approximately 10.4 pM) and high specificity. Results using the truncated variants indicated that the seven residues at the N terminus affected the binding kinetics; when removed, the binding characteristics changed from fast to slow. Further, the thrombin active site binding moiety of variegin is in the region of residues 8-14, and the exosite-I binding moiety is within residues 15-32. Our results show that variegin is structurally and functionally similar to the rationally designed thrombin inhibitor, hirulog. However, compared with hirulog, variegin is a more potent inhibitor, and its inhibitory activity is largely retained after cleavage by thrombin.
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spelling oxford-uuid:dd7daf03-abc4-443c-b5a3-89a5c6542f9e2022-03-27T09:25:23ZVariegin, a novel fast and tight binding thrombin inhibitor from the tropical bont tick.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:dd7daf03-abc4-443c-b5a3-89a5c6542f9eEnglishSymplectic Elements at Oxford2007Koh, CKazimirova, MTrimnell, ATakac, PLabuda, MNuttall, PKini, RTick saliva contains potent antihemostatic molecules that help ticks obtain their enormous blood meal during prolonged feeding. We isolated thrombin inhibitors present in the salivary gland extract from partially fed female Amblyomma variegatum, the tropical bont tick, and characterized the most potent, variegin, one of the smallest (32 residues) thrombin inhibitors found in nature. Full-length variegin and two truncated variants were chemically synthesized. Despite its small size and flexible structure, variegin binds thrombin with strong affinity (K(i) approximately 10.4 pM) and high specificity. Results using the truncated variants indicated that the seven residues at the N terminus affected the binding kinetics; when removed, the binding characteristics changed from fast to slow. Further, the thrombin active site binding moiety of variegin is in the region of residues 8-14, and the exosite-I binding moiety is within residues 15-32. Our results show that variegin is structurally and functionally similar to the rationally designed thrombin inhibitor, hirulog. However, compared with hirulog, variegin is a more potent inhibitor, and its inhibitory activity is largely retained after cleavage by thrombin.
spellingShingle Koh, C
Kazimirova, M
Trimnell, A
Takac, P
Labuda, M
Nuttall, P
Kini, R
Variegin, a novel fast and tight binding thrombin inhibitor from the tropical bont tick.
title Variegin, a novel fast and tight binding thrombin inhibitor from the tropical bont tick.
title_full Variegin, a novel fast and tight binding thrombin inhibitor from the tropical bont tick.
title_fullStr Variegin, a novel fast and tight binding thrombin inhibitor from the tropical bont tick.
title_full_unstemmed Variegin, a novel fast and tight binding thrombin inhibitor from the tropical bont tick.
title_short Variegin, a novel fast and tight binding thrombin inhibitor from the tropical bont tick.
title_sort variegin a novel fast and tight binding thrombin inhibitor from the tropical bont tick
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