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Characterization of acrosin‐like activity of lake sturgeon ( Acipenser fulvescens ) spermatozoa
Author(s) -
Ciereszko Andrzej,
Dabrowski Konrad,
Ochkur Sergei I.
Publication year - 1996
Publication title -
molecular reproduction and development
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.745
H-Index - 105
eISSN - 1098-2795
pISSN - 1040-452X
DOI - 10.1002/(sici)1098-2795(199609)45:1<72::aid-mrd10>3.0.co;2-z
Subject(s) - acrosin , sperm , extender , biology , cryoprotectant , milt , hydrolysis , biochemistry , andrology , chemistry , acrosome , microbiology and biotechnology , cryopreservation , botany , medicine , embryo , organic chemistry , polyurethane
Acipenserid fish sperm possess trypsin‐like activity, resembling acrosin activity of mammalian sperm, which can be measured by hydrolysis of N‐α‐benzoyl‐DL‐arginine p‐nitroanilide (BAPNA) Ciereszko et al., 1994: J Exp Zool 268:486–491). We found that this activity can be preserved when sperm is frozen on dry ice with 0.6 M sucrose‐10% dimethylsulfoxide (DMSO) extender (sperm:extender ratio 1:3), and subsequently stored in liquid nitrogen. However, other methods of freezing (without cryoprotectant at −18°C, −80°C, and −196°C) did not protect this activity. Acrosin‐like activity decreased in the course of storage of milt on ice; 88% decline was recorded after 13 days. Acrosin‐like activity increased with temperature from 10°C to 30°C, but was inactivated at 40°C to about 40% as compared to the optimum temperature. Triton X‐100 inhibited activity by 15% and 72% at 0.01% and 0.1% concentrations, respectively. Activity was not affected by Mg 2+ but was inhibited by Zn 2+ (30% and 75% in the presence of 0.1 mM and 1 mM, respectively). Maximum velocity of substrate hydrolysis was observed at 2 mM of BAPNA. Acrosin‐like activity was effectively inhibited by 4′‐acetamidopheny1 4‐guanidinobenzoate (AGB), an inhibitor of mammalian acrosin. Sperm acrosin‐like activity correlated negatively with anti‐proteinase activity of seminal plasma. We conclude that sturgeon acrosin‐like activity shares many properties with mammalian acrosin. On the other hand, it has some unique properties which may represent adaptations of this enzyme to the environment of external fertilization. © 1996 Wiley‐Liss, Inc.