Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: EC:3.4.21.1 (
chymotrypsin
)
10,938
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Headpin (SERPINB13) is a novel member of the serine proteinase inhibitor (Serpin) gene family that was originally cloned from a keratinocyte cDNA library. Western blot analysis using a
headpin
-specific antiserum recognized a protein with the predicted M(r) of 44kDa in lysates derived from a transformed keratinocyte cell line known to express
headpin
mRNA. Similarity of the reactive-site loop (RSL) domain of
headpin
, notably at the P1-P1(') residues, with other serpins that inhibit cysteine and serine proteinases suggests that
headpin
may inhibit similar proteinases. This study demonstrates that recombinant
headpin
indeed inhibits cathepsins K and L, but not
chymotrypsin
, elastase, trypsin, subtilisin A, urokinase-type plasminogen activator, plasmin, or thrombin. The second-order rate constants (k(a)) for the inhibitory reactions of rHeadpin with cathepsins K and L were 5.1+/-0.6x10(4) and 4.1+/-0.8x10(4)M(-1)s(-1), respectively. Headpin formed SDS-stable complexes with cathepsins K and L, a characteristic property of inhibitory serpins. Interactions of the RSL domain of
headpin
with cathepsins K and L were indicated by cleavage of
headpin
near the predicted P1-P1(') residues by these proteinases. These results demonstrate that the serpin
headpin
possesses specificity for inhibiting lysosomal cysteine proteinases.
...
PMID:Inhibition of the cysteine proteinases cathepsins K and L by the serpin headpin (SERPINB13): a kinetic analysis. 1250 4
