Structural basis for regulation of stability and activity in glyceraldehyde-3-phosphate dehydrogenases. Differential scanning calorimetry and molecular dynamics.

Tissue specific isoforms of human glyceraldehyde-3-phosphate dehydrogenase, somatic (GAPD) and sperm-specific (GAPDS), have been reported to display different levels of both stability and catalytic activity. Here we apply MD simulations to investigate molecular basis of this phenomenon. The protein is a tetramer where each subunit consists of two domains - catalytic and NAD-binding one.

Sperm-specific glyceraldehyde-3-phosphate dehydrogenase is expressed in melanoma cells.

Sperm-specific glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDS) is normally expressed only in sperms, but not in somatic tissues. Analysis of the expression of GAPDS mRNA in different cancer cell lines shows that the content of GAPDS mRNA is enhanced in some lines of melanoma cells. The purpose of the study was to assay melanoma cells for the expression of protein GAPDS.

Isolation of antibodies against different protein conformations using immunoaffinity chromatography.

A polyclonal antiserum obtained after the immunization of a rabbit with recombinant human sperm-specific glyceraldehyde-3-phosphate dehydrogenase lacking in 68 N-terminal amino acid residues (dN-GAPDS) was purified using different immunosorbents with immobilized dN-GAPDS in the native or denatured states. The procedure resulted in isolation of two types of polyclonal antibodies. The first type interacted with native recombinant dN-GAPDS as well as with native human sperm-specific glyceraldehyde-3-phosphate dehydrogenase, not cross-reacting with muscle glyceraldehyde-3-phosphate dehydrogenase (GAPD).

Chaperonin TRiC assists the refolding of sperm-specific glyceraldehyde-3-phosphate dehydrogenase.

The cytosolic chaperonin TRiC was isolated from ovine testes using ultracentrifugation and heparin-Sepharose chromatography. The molecular mass of the obtained preparation was shown to exceed 900 kDa (by Blue Native PAGE). SDS-PAGE yielded a set of bands in the range of 50-60 kDa.

Testis-specific glyceraldehyde-3-phosphate dehydrogenase: origin and evolution.

Background: Glyceraldehyde-3-phosphate dehydrogenase (GAPD) catalyses one of the glycolytic reactions and is also involved in a number of non-glycolytic processes, such as endocytosis, DNA excision repair, and induction of apoptosis. Mammals are known to possess two homologous GAPD isoenzymes: GAPD-1, a well-studied protein found in all somatic cells, and GAPD-2, which is expressed solely in testis. GAPD-2 supplies energy required for the movement of spermatozoa and is tightly bound to the sperm tail cytoskeleton by the additional N-terminal proline-rich domain absent in GAPD-1.