PMID- 2065053
OWN - NLM
STAT- MEDLINE
DCOM- 19910812
LR  - 20190613
IS  - 0006-2960 (Print)
IS  - 0006-2960 (Linking)
VI  - 30
IP  - 27
DP  - 1991 Jul 9
TI  - Deciphering the structural elements of hirudin C-terminal peptide that bind to 
      the fibrinogen recognition site of alpha-thrombin.
PG  - 6656-61
AB  - The C-terminal peptide of a hirudin acts as an anticoagulant by binding 
      specifically to a noncatalytic (fibrinogen recognition) site of thrombin. This 
      binding has been shown to shield five spatially distant lysines of the thrombin 
      B-chain (Lys21, Lys65, Lys77, Lys106, and Lys107). It was also demonstrated that 
      modification of the sequence of the hirudin C-terminal peptide invariably 
      diminished its anticoagulant activity. The major object of this study is to 
      investigate how the decreased activity of the modified hirudin C-terminal peptide 
      is reflected by the change of its binding properties to these five lysines of 
      thrombin. A synthetic peptide representing the last 12 C-terminal amino acids of 
      hirudin (Hir54-65) was (1) truncated from both its N-terminal and its C-terminal 
      ends, or (2) substituted with Gly along residues 57-62, or (3) chemically 
      modified to add (sulfation at Tyr63) or abolish (Asp and Glu modification with 
      carbodiimide/glycinamide) its negatively charged side chains. The binding 
      characteristics of these peptides to thrombin were investigated by chemical 
      methods, and their corresponding anticoagulant activities were studied. Our 
      results demonstrated the following: (1) the anticoagulant activities of hirudin 
      C-terminal peptides were quantitatively related to their abilities to shield the 
      five identified lysines of thrombin. The most potent peptide was sulfated 
      Hir54-65 (S-Hir54-65) with an average binding affinity to the five lysines of 120 
      nM. A heptapeptide (Hir54-60) also displayed anticoagulant activity and thrombin 
      binding ability at micromolar concentrations. (2) All active hirudin C-terminal 
      peptides regardless of their sizes and potencies were shown to be capable of 
      shielding the five lysines of thrombin.(ABSTRACT TRUNCATED AT 250 WORDS)
FAU - Chang, J Y
AU  - Chang JY
AD  - Pharmaceuticals Research Laboratory, Ciba-Geigy Ltd., Basel, Switzerland.
LA  - eng
PT  - Journal Article
PL  - United States
TA  - Biochemistry
JT  - Biochemistry
JID - 0370623
RN  - 0 (Anticoagulants)
RN  - 0 (Hirudins)
RN  - 0 (Peptide Fragments)
RN  - 9001-32-5 (Fibrinogen)
RN  - EC 3.4.21.4 (Trypsin)
RN  - EC 3.4.21.5 (Thrombin)
SB  - IM
MH  - Amino Acid Sequence
MH  - Anticoagulants
MH  - Chromatography, High Pressure Liquid
MH  - Fibrinogen/*metabolism
MH  - Hirudins/genetics/*metabolism/pharmacology
MH  - Humans
MH  - Molecular Sequence Data
MH  - Peptide Fragments/*metabolism/pharmacology
MH  - Peptide Mapping
MH  - Substrate Specificity
MH  - Thrombin/*metabolism
MH  - Trypsin
EDAT- 1991/07/09 00:00
MHDA- 1991/07/09 00:01
CRDT- 1991/07/09 00:00
PHST- 1991/07/09 00:00 [pubmed]
PHST- 1991/07/09 00:01 [medline]
PHST- 1991/07/09 00:00 [entrez]
AID - 10.1021/bi00241a004 [doi]
PST - ppublish
SO  - Biochemistry. 1991 Jul 9;30(27):6656-61. doi: 10.1021/bi00241a004.