Overview of GMPPA and Its Biological Role

GMPPA (GDP-mannose pyrophosphorylase A) is one of two paralogous subunits—alongside GMPPB—that constitute the GDP-mannose pyrophosphorylase enzyme complex. This enzyme catalyzes the synthesis of GDP-mannose from GTP and mannose-1-phosphate, a critical step in the biosynthesis of mannose-containing glycans. GDP-mannose serves as the essential sugar-nucleotide donor for mannosylation reactions integral to N-linked and O-linked glycosylation, as well as GPI-anchor biosynthesis.

Unlike GMPPB, GMPPA is considered a regulatory, catalytically attenuated subunit that modulates overall enzyme activity and may function in feedback regulation of GDP-mannose levels within the cell. Mutations in GMPPA have been associated with alacrima, achalasia, and mental retardation syndrome (AAMR syndrome), underscoring its physiological importance.

Product Specifications and Quality

Recombinant Human GMPPA Protein (SKU: rp367981) is produced using established recombinant expression systems to ensure high purity and biological relevance. Researchers should consult the product datasheet (reference: absea#PP-5801) for precise information on the following parameters:

• Purity: Verify purity grade by SDS-PAGE or equivalent method as stated in the datasheet.
• Formulation: Check buffer composition, protein concentration, and any carrier additives (e.g., BSA, glycerol) listed on the datasheet.
• Tag Information: Note any affinity or epitope tags (e.g., His-tag, GST) that may influence downstream assay design.
• Biological Activity: Confirm whether functional or binding activity data are provided in the datasheet.

All specific numerical values for purity, concentration, and molecular weight should be verified against the current product datasheet prior to experimental use.

Handling, Reconstitution, and Storage Protocol

Proper handling of Recombinant Human GMPPA Protein is critical to maintaining its structural integrity and functional activity. Adhere to the following general guidelines, and always cross-reference with the specific instructions provided in the product datasheet:

1. Receipt and Inspection: Upon receipt, immediately inspect the product for correct labeling, integrity of packaging, and appropriate shipping condition. Document lot number and expiry date.
2. Reconstitution: If supplied as a lyophilized powder, reconstitute with the volume and buffer recommended in the datasheet (typically sterile water or PBS). Allow the vial to equilibrate to room temperature before opening. Gently pipette to mix; do not vortex.
3. Aliquoting: Prepare single-use aliquots immediately after reconstitution to minimize protein degradation from repeated freeze-thaw cycles.
4. Storage: Store aliquots at the temperature specified in the datasheet (commonly -20°C or -80°C for long-term storage). Avoid repeated freeze-thaw cycles, as these reduce protein activity.
5. Working Conditions: Keep the protein on ice during experimental setup. Use low-protein-binding tubes to minimize adsorption losses.

Recommended Research Applications

Recombinant Human GMPPA Protein is suitable for a range of in vitro research applications. The following uses are commonly associated with recombinant proteins of this class:

• Enzymatic and Biochemical Assays: Use as a component in reconstituted GDP-mannose pyrophosphorylase activity assays to study enzyme kinetics and inhibitor screening.
• Protein–Protein Interaction Studies: Suitable for co-immunoprecipitation (Co-IP), pull-down assays, or surface plasmon resonance (SPR) studies to identify GMPPA binding partners, including GMPPB.
• Structural Biology: May be used as antigen for antibody production or as a standard in Western blot and ELISA validation experiments.
• Cell-Free Systems: Applicable in cell-free transcription/translation or pathway reconstitution experiments investigating mannose metabolism.
• Disease Mechanism Research: Useful as a tool protein for investigating the molecular basis of AAMR syndrome and congenital disorders of glycosylation (CDG).

Researchers should validate the protein in their specific assay system and refer to the current datasheet for confirmed application data.