glycophorin

Supported member assignment

Record evidence sufficient to distinguish a particular member from an unresolved glycophorin preparation.

1. Does glycophorin identify the class, a specific member or a mixture in this record? definition
2. Which species, versioned protein accession and identification method support the assignment? provenance

Actual chain identity

Define the chain present without confusing mature protein, precursor, hybrid or fragment.

1. What sequence and residue numbering describe the mature chain or experimental construct? definition
2. Is the observed difference an inherited variant, hybrid sequence, processing event or preparation-induced cleavage? boundary

Measured glycoform

Separate directly measured glycan features from sequence predictions or assumptions about the expression host.

1. Which N-linked and O-linked sites, occupancies and glycan compositions are experimentally supported? measurement
2. What sialic acid content and linkage information were measured, using which method and normalization? measurement

Interpretable molecular profile

Keep backbone mass, glycosylated mass, apparent gel mass and assembly effects distinguishable.

1. Does each reported mass represent a calculated chain, intact glycoprotein, apparent gel band or molecular assembly? boundary
2. What evidence explains changes following desialylation, deglycosylation or proteolysis? measurement

Verified presentation

Record whether relevant domains are intact and accessible in cells, vesicles or reconstituted membranes.

1. Which residues occupy extracellular, transmembrane and cytoplasmic regions for this member? definition
2. What evidence establishes orientation and accessible fraction in this cell or membrane preparation? measurement

Contextual association

Separate measured association from assumed family-wide behavior; glycophorin A has documented ankyrin-complex and SLC4A1 relationships in [UniProt GYPA](https://www.uniprot.org/uniprotkb/P02724/entry).

1. Which oligomeric state and membrane or cytoskeletal partners are supported for this member? provenance
2. Were these associations observed in intact cells, detergent, a membrane mimic or an isolated domain? boundary

Member-specific antigen evidence

Distinguish an antigen-bearing protein from a complete blood group phenotype; human glycophorins A and B bear MN and Ss determinants respectively in the [NCBI GYPA record](https://www.ncbi.nlm.nih.gov/gene/2993).

1. Which antigen or epitope is supported for this sequence, glycoform and species? definition
2. Could reduced probe binding reflect epitope alteration or masking rather than loss of glycophorin? boundary

Controlled recognition

Require specificity controls and distinguish molecular binding from downstream biological outcomes.

1. Which named ligand binds this member, and what controls exclude cross-reactivity or nonspecific membrane binding? measurement
2. How do sequence variation, glycan treatment and presentation affect the measured interaction? measurement
3. What additional evidence is needed before using binding to predict a cellular or pathogen-related outcome? boundary

Traceable preparation

Connect each preparation to its biological source or construct and document features limiting comparison.

1. Was the material obtained from erythrocytes, another biological source or a specified recombinant expression system? provenance
2. Which co-purified membrane proteins, residual lipids, tags or host-dependent glycans could affect its intended use? boundary

Qualified use state

Define preparation-specific acceptance criteria using observed stability rather than generic small-molecule constants.

1. What measurements establish intact protein, aggregation, concentration and retained epitope or ligand accessibility? measurement
2. Which buffer, detergent or lipid environment, temperature and freeze-thaw history preserve those properties? measurement
3. Should this preparation be used, recharacterized or rejected for the proposed assay based on its acceptance criteria? action

Check these first

Recalled without web access and unsourced; every item is a lead to verify.

1. Which of these check these first hold for the sense of glycophorin this model covers, and on what evidence? provenance

Kinds and varieties

Recalled without web access and unsourced; every item is a lead to verify.

1. Which of these kinds and varieties hold for the sense of glycophorin this model covers, and on what evidence? provenance

Identifiers and schemes

Recalled without web access and unsourced; every item is a lead to verify.

1. Which of these identifiers and schemes hold for the sense of glycophorin this model covers, and on what evidence? provenance

Standards and regulation

Recalled without web access and unsourced; every item is a lead to verify.

1. Which of these standards and regulation hold for the sense of glycophorin this model covers, and on what evidence? provenance

Real-world use

Recalled without web access and unsourced; every item is a lead to verify.

1. Which of these real-world use hold for the sense of glycophorin this model covers, and on what evidence? provenance

Typical measurements

Recalled without web access and unsourced; every item is a lead to verify.

1. Which of these typical measurements hold for the sense of glycophorin this model covers, and on what evidence? provenance

Failure modes and hazards

Recalled without web access and unsourced; every item is a lead to verify.

1. Which of these failure modes and hazards hold for the sense of glycophorin this model covers, and on what evidence? provenance

Regional variation

Recalled without web access and unsourced; every item is a lead to verify.

1. Which of these regional variation hold for the sense of glycophorin this model covers, and on what evidence? provenance

Neighbouring kinds and how to tell them apart

Recalled without web access and unsourced; every item is a lead to verify.

1. Which of these neighbouring kinds and how to tell them apart hold for the sense of glycophorin this model covers, and on what evidence? provenance