scholarly journals SPECIFICITY IN THE INDUCTION OF POLYSPERMY IN SEA URCHIN EGGS BY SOYBEAN TRYPSIN INHIBITOR

1984 ◽  
Vol 166 (3) ◽  
pp. 473-481 ◽  
Author(s):  
MARK C. ALLIEGRO ◽  
HERBERT SCHUEL
Keyword(s):  
Sea Urchin ◽  
Trypsin Inhibitor ◽  
Soybean Trypsin Inhibitor ◽  
Sea Urchin Eggs

Evidence that hatching enzyme of the sea urchin Strongylocentrotus purpuratus is a chymotrypsin-like protease

1988 ◽  
Vol 66 (11) ◽  
pp. 1200-1209 ◽  
Author(s):  
Laura L. Post ◽  
Regina Schuel ◽  
Herbert Schuel
Keyword(s):  
Ethyl Ester ◽  
Proteolytic Activity ◽  
Sea Urchin ◽  
Trypsin Inhibitor ◽  
Strongylocentrotus Purpuratus ◽  
Soybean Trypsin Inhibitor ◽  
Chloromethyl Ketone ◽  
Hatching Enzyme ◽  
Sea Urchin Eggs ◽  
Chymotrypsin Inhibitors

The sea urchin blastula secretes a hatching enzyme (HE) that dissolves the fertilization envelope. HE was collected from the supernatant seawater of cultures of hatched Strongylocentrotus purpuratus blastulae, and concentrated 20 times by ultrafiltration. The proteolytic activity of HE using casein as substrate was inhibited by the chymotrypsin inhibitors, chymostatin and N-tosyl-L-phenylalanine chloromethyl ketone. The activity was not inhibited by inhibitors (antipain, elastatinal, pepstatin, phosphoramidon, soybean trypsin inhibitor, and Nα-p-tosyl-L-lysine chloromethyl ketone) of other types of proteases. HE did not hydrolyze the synthetic trypsin substrate, α-N-benzoyl-L-arginine ethyl ester, but did hydrolyze the synthetic substrate of chymotrypsin, N-benzoyl-L-tyrosine ethyl ester (BTEE). The BTEEase activity of HE was completely inhibited by the chymotrypsin inhibitors chymostatin and 2-nitro-4-carboxyphenyl N,N-diphenylcarbamate (NCDC). Chymostatin inhibited the natural hatching of sea urchin blastulae. Application of HE to freshly fertilized sea urchin eggs, 2 h after insemination, caused premature dispersal of the hardened fertilization envelope. Chymostatin and NCDC inhibited HE-induced lysis of the fertilization envelope, while inhibitors of other types of proteases were ineffective. These data suggest that sea urchin HE is a chymotrypsin-like protease we call "chymostrypsin."

Factor X Activation by washed human platelets

1979 ◽  
Author(s):  
E van Wijk ◽  
L Kahlé ◽  
J ten Cate
Keyword(s):  
Human Factors ◽  
Trypsin Inhibitor ◽  
Calcium Ions ◽  
Factor Xa ◽  
Human Platelets ◽  
Soybean Trypsin Inhibitor ◽  
Thrombin Inhibitor ◽  
Chromogenic Substrate ◽  
Factor X ◽  
Factor X Activation

In a system of washed human platelets, Ca2+and purified human factors X anc II, a sufficient amount of thrombin is generated in about 10 minutes to aggregate the platelets. This thrombin is formed through the activation of FX by the platelets. In a system with either FX or FII present, no aggregation occurs. In addition no aggregation is observed when hirudin, a specific thrombin inhibitor, or when soybean trypsin inhibitor, which inhibits factor Xa, are added to the mixture. The formation of factor Xa can be monitored indirectly through the generation of thrombin, in the presence of an excess of prothrombin, using a thrombin sensitive chromogenic substrate. When washed platelets are incubated with FX alone for 10 minutes, no aggregation occurs and after the addition of prothrombin aggregation starts within 6 minutes. These findings confirm that washed platelets possess a factor X activating property. The generation of FXa proceeds in the absence of added Ca2+, whereas in the presence of Ca2+factor Xa activity reaches a maximum in 3 minutes, whereafter the activity progressively decreases. This may be due to the binding of Xa to the platelets in the presence of calcium ions.

scholarly journals Identification of polysialic acid-containing glycoprotein in the jelly coat of sea urchin eggs. Occurrence of a novel type of polysialic acid structure.

1994 ◽  
Vol 269 (36) ◽  
pp. 22712-22718 ◽  
Author(s):  
S. Kitazume ◽  
K. Kitajima ◽  
S. Inoue ◽  
F.A. Troy ◽  
J.W. Cho ◽  
...  
Keyword(s):  
Sea Urchin ◽  
Polysialic Acid ◽  
Sea Urchin Eggs ◽  
Jelly Coat ◽  
Acid Structure
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