Mapping of epitopes relevant for induction of acrosome reaction on human zona pellucida glycoprotein-4 using monoclonal antibodies.

Problem: To decipher structural and functional aspects of human zona pellucida glycoprotein-4 (ZP4), the epitopes recognized by monoclonal antibodies (MAbs) have been mapped.

Method Of Study: Recombinant human ZP4-mediated induction of acrosome reaction in human sperm was studied in the absence and presence of ZP4-specific MAbs. The epitopes of MAbs were mapped using recombinant peptides expressed in Escherichia coli.

Anti-HIV activity of semisynthetic derivatives of andrographolide and computational study of HIV-1 gp120 protein binding.

Andrographolide, a diterpene lactone of the Andrographis paniculata, displays anti-HIV activity in vitro. A series of andrographolide derivatives have been synthesized and evaluated for their anti-HIV activity in a cell-free virus infectivity assay using TZM-bl cells. As compared to andrographolide, 3-nitrobenzylidene derivative 6 showed higher in vitro anti-HIV activity, whereas 2',6'-dichloro-nicotinoyl ester derivative 9 showed higher Therapeutic Index.

Mammalian zona pellucida glycoproteins: structure and function during fertilization.

Zona pellucida (ZP) is a glycoproteinaceous translucent matrix that surrounds the mammalian oocyte and plays a critical role in the accomplishment of fertilization. In humans, it is composed of 4 glycoproteins designated as ZP1, ZP2, ZP3 and ZP4, whereas mouse ZP is composed of ZP1, ZP2 and ZP3 (Zp4 being a pseudogene). In addition to a variable sequence identity of a given zona protein among various species, human ZP1 and ZP4 are paralogs and mature polypeptide chains share an identity of 47%.

Acrosome reaction: relevance of zona pellucida glycoproteins.

During mammalian fertilisation, the zona pellucida (ZP) matrix surrounding the oocyte is responsible for the binding of the spermatozoa to the oocyte and induction of the acrosome reaction (AR) in the ZP-bound spermatozoon. The AR is crucial for the penetration of the ZP matrix by spermatozoa. The ZP matrix in mice is composed of three glycoproteins designated ZP1, ZP2 and ZP3, whereas in humans, it is composed of four (ZP1, ZP2, ZP3 and ZP4).

In humans, zona pellucida glycoprotein-1 binds to spermatozoa and induces acrosomal exocytosis.

Background: It has been suggested that the zona pellucida (ZP) may mediate species-specific fertilization. In human the ZP is composed of four glycoproteins: ZP1, ZP2, ZP3 and ZP4. In the present study, the expression profile of ZP1 in human oocytes and ovaries, and its role during fertilization, is presented.

Delineation of downstream signalling components during acrosome reaction mediated by heat solubilized human zona pellucida.

Background: Human egg is enveloped by a glycoproteinaceous matrix, zona pellucida (ZP), responsible for binding of the human spermatozoa to the egg and induction of acrosomal exocytosis in the spermatozoon bound to ZP. In the present manuscript, attempts have been made to delineate the downstream signalling components employed by human ZP to induce acrosome reaction.

Methods: Heat-solubilized human ZP (SIZP) was used to study the induction of acrosome reaction in capacitated human spermatozoa using tetramethylrhodamine isothiocyanate conjugated Pisum sativum agglutinin (TRITC-PSA) in absence or presence of various pharmacological inhibitors.

Human zona pellucida glycoproteins: functional relevance during fertilization.

The zona pellucida (ZP), a glycoproteinaceous matrix surrounding the mammalian oocyte plays an important role in species-specific sperm-egg binding, induction of acrosome reaction in the ZP-bound spermatozoa, avoidance of polyspermy and protection of the embryo prior to implantation. In contrast to mouse, human ZP matrix is composed of 4 glycoproteins designated as ZP1, ZP2, ZP3 and ZP4 (Zp4 pseudogene in mouse). Recent studies employing recombinant and immunoaffinity purified human zona proteins revealed that in addition to ZP3, capacitated acrosome-intact spermatozoa also bind ZP4.

Structural and functional attributes of zona pellucida glycoproteins.

A translucent matrix termed the zona pellucida (ZP) surrounds the mammalian oocyte. It plays a critical role in fertilization by acting as a "docking site" for binding of spermatozoa followed by induction of the acrosome reaction in the zona bound sperm. Recent analyses of the genes of the human oocyte revealed that the ZP matrix is composed of four glycoproteins, designated as ZP1, ZP2, ZP3 and ZP4, instead of 3 found in the mouse ZP.