1997 Fiscal Year Final Research Report Summary
Signal molecules in the jelly coat of starfish eggs for the inducing of acrosome reaction.
| Project/Area Number |
08458237
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Developmental biology
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| Research Institution | Tokyo Institute of Technology |
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Principal Investigator |
HOSHI Motonori Tokyo Inst.of Tech.Fac of Life Sci.& Tech.Professor, 生命理工学部, 教授 (20012411)
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| Co-Investigator(Kenkyū-buntansha) |
CHIBA Kazuyoshi Ochanomizu Women's Univ.Fac.of Science Associate Prof., 理学部, 助教授 (70222130)
MATSUMOTO Midori Tokyo Inst.of Tech.Fac of Life Sci.& Tech.Assistant Prof., 生命理工学部, 助手 (00211574)
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| Project Period (FY) |
1996 – 1997
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| Keywords | acrosome reaction / sperm-egg binding / starfish / キヒトデ |
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| Research Abstract |
The acrosome reaction (AR) is a species-specific exocytosis response of spermatozoa to the egg envelopment. In the starfish Asterias amurensis, three components in the jelly coat of eggs act in concert on spermatozoa to elicit the AR ; namely acrosome reaction-inducing substance (ARIS), Co-ARISs and sperm-activating peptides named asterosaps. ARIS is highly sulfated glycoprotein of an apparent molecular size over 10^7 and its activity is mostly attributable to sulfated sugar chains. The main saccharide chain of ARIS is a very long (2 x 10^6 in more in molecular size) linear polymer of the pentasaccharide repeating units (Fr.1) is able to induce the AR at high calcium concentration as well as ARIS does. To obtain binding parameters of an ARIS receptor, binding experiments were carried out by centrifugation binding assay using radio-labeled Fr.1. Spermatozoa were incubated with radioactive iodinated Fr.1. With Scatchard plot, there are two type receptor, High affinity type (Kd ; 145 muM,Bmax ; 8.38 x 10^4) and low affinity type (Kd ; 4.43 x 10^2muM,Bmax ; 1.89 x 10^6). And competitive assay were carried with non-labeled Fr.1 and ^<125>I labeled Fr.1. The bound and free concentration of the ligand were measured. The result showed that non-labeled Fr.1 inhibits to bind labeled Fr.1.
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