Human B-chain secretion and A2B2 reconstitution are directly supported by the inspected Methods and Results of PMID:26247044. B supplies a carrier/assembly role; A supplies the transglutaminase chemistry. The inherited coagulation contexts are retained on that role, without turning clinical necessity into an isolated enzyme assay. PMID:2334637 and the mouse-donor PMID:18224415 supply positive stability/rescue observations at abstract-only scope.
The actual 2016 PMID:27363989 experiment perturbs A-chain constructs expressed in COS-1 cells and includes A2B2 as an assay control. Its use for a B-chain IDA is retained as a suspected provenance question, separate from the supported biological process. Complex-level positive controls can legitimately support projected component participation, so lack of an isolated B perturbation does not itself establish a wrong code. Live ComplexPortal CPX-6231 and Reactome agree on native A2B2 association; the Reactome activated A-plus-calcium state excludes B. Complex membership must not imply that B is an intrinsic transferase or remains bound throughout catalysis.
P05160 is explicitly present in the recovered PMID:14718574 Table II plasma-proteome row. This and B secretion corroborate extracellular localization while the complete 1973 original remains unavailable. The 661-residue precursor, its signal/chain processing features and separate predicted products are not conflated. Detailed public locators and actual read boundaries are in the source guide.
No new annotation or quotation was added. Description, core synthesis, questions and compilation status remain deferred to the next phase; no provider report was authored.
Human B secretion and reconstitution with recombinant A2 establish an assembly contribution. The 2015 assays quantify cleared-medium B antigen and A2B2 antigen normalized to B; they do not measure a B-chain transferase reaction or directed delivery to another molecule. The historical human deficiency abstract and mouse rescue with human B support maintenance of circulating A, while their complete original Methods remain unavailable. The new standalone description and single core preserve this positive role without transferring F13A1 catalysis to F13B. PMID:26247044(https://pmc.ncbi.nlm.nih.gov/articles/PMC4521963/), PMID:2334637(https://doi.org/10.1111/j.1365-2141.1990.tb02585.x), PMID:18224415(https://doi.org/10.1007/s12185-007-0005-z)
The core uses the existing fibrin-clot-formation process without also repeating its blood-coagulation ancestor. Its transferase-complex membership refers to the B-containing precursor assembly. The actual Reactome output after activation contains A and calcium while B is released; complex membership does not establish B catalytic contribution. Reactome R-HSA-140847
No molecular-function ID is forced onto the carrier/assembly role. Current protein carrier activity requires delivery to an acceptor or location; protein-containing complex stabilizing activity requires blocking a factor that promotes dissociation. Neither precise mechanism follows from assembly antigen and plasma-protein survival alone. This bounded curation gap, paired question and experiment leave the established biological role intact. All 11 accepted source/review objects, 11 references and the single SUSPECTED/CHECK source query remain exact; status stays INITIALIZED for later canonical computation. No NEW annotation or publication quotation is introduced.
F13B's noncatalytic assembly and maintenance of circulating A remain supported. The former CURATION-only knowledge gap described term selection, so it is removed rather than relabeled as a biological unknown. The focused assembly/loss/release question and experiment remain; omitting a molecular-function identifier does not erase the established carrier role.
Protein stabilization, GO:0050821 was assessed explicitly. Its definition and parent concern protein structure/integrity and degradation or aggregation. Human B–A2 reconstitution directly measures assembly, while the historical human deficiency and mouse rescue abstracts measure plasma persistence or abundance. These support maintenance of circulating A but do not distinguish removal of intact protein from protection against degradation or aggregation. NEW is deferred on this inspected evidence; this is a limit on the proposed ontology assertion, not a denial of the established physiological stabilization role. The source guide records the participation, same-role comparator, GO-CAM and nonredundancy checks. PMID:26247044(https://pmc.ncbi.nlm.nih.gov/articles/PMC4521963/), PMID:2334637(https://doi.org/10.1111/j.1365-2141.1990.tb02585.x), PMID:18224415(https://doi.org/10.1007/s12185-007-0005-z)
The three broad coagulation assertions remain ACCEPT because fibrin-clot formation is part of blood coagulation; the core avoids repeating that broader process. The row-9 evidence-code defect is removed: complex-level positive controls can support component participation, and the inspected evidence does not establish a wrong IDA. The A2B2 precursor versus activated A-plus-calcium representation is now an explicit ontology question, not a new biological annotation.
The standing campaign instruction forbids new publication quotations and takes precedence over the requested supporting_text additions. Reference-only support and public paper-section/table locators are retained. Complete-original availability remains separate from immutable publication-cache metadata: the Bonn thesis supplies the reproduced PMID:27363989 main article and supplement, while the PMID:14718574 recovery is limited to selected original sections and Table II. No availability flags or cached source bytes are changed. Earlier journal entries describe their historical checkpoints.
The broad molecular function structural molecule activity, GO:0005198 is now assigned specifically to the B-containing precursor complex. The current definition concerns structural integrity. In the human B-expression/reconstitution experiment, fixed recombinant A2 and secreted wild-type or mutant B produced an A2B2 antigen endpoint normalized to B antigen; several B mutants selectively reduced assembly. That target-specific complex-assembly phenotype supports a broad structural contribution, while leaving the precise stabilizing mechanism unresolved. A NEW IMP annotation records the mutant evidence and the core names the same molecular function. PMID:26247044(https://pmc.ncbi.nlm.nih.gov/articles/PMC4521963/), Methods “Cell culture, transfection, and protein expression and quantification” and “Expression and reconstitution study,” corresponding Results and Figure 3 caption.
This does not assign transglutaminase activity to B or place it in the activated A-plus-calcium complex. It also does not resolve the previously deferred protein-stabilization mechanism. A broad structural contribution and a specific degradation/aggregation or dissociation-prevention mechanism have different evidence requirements. The guide records the explicit same-role comparison and source limits. Earlier notes retain their historical molecular-function search decision.