| Category | Concise statement | Evidence type | Citations |
|---|---|---|---|
| Identity/Structure | UniProt K9IMD0 is the **Desmodus rotundus LTF/lactotransferrin (lactoferrin) precursor**; vampire-bat salivary studies recovered a partial draculin-1 sequence and placed it within the **lactotransferrin family**, aligned to human/horse LTF, supporting the UniProt assignment of draculin as an LTF-like scaffold. | Experimental in *D. rotundus* (sequence/proteomics) | (pqac-00000000, pqac-00000001, pqac-00000034, pqac-00000035) |
| Identity/Structure | Across mammals, lactoferrin is an ~80 kDa, ~700 aa, **bilobed transferrin-family glycoprotein** with N- and C-lobes, each binding one Fe3+; glycosylation affects stability, proteolysis resistance, and receptor interactions. | Lactoferrin-family / human-bovine evidence | (pqac-00000005, pqac-00000010, pqac-00000011) |
| Localization | In vampire bat, draculin/LTF-like protein is **secreted from submaxillary glands** and proteomically detected in salivary gland secretions; lactotransferrin is also detected in accessory gland proteomes. | Experimental in *D. rotundus* | (pqac-00000001, pqac-00000002, pqac-00000004, pqac-00000039) |
| Localization | In other mammals, lactoferrin localizes to **exocrine/mucosal secretions** (milk, saliva, tears, genital and respiratory secretions) and to **neutrophil secondary granules**, where it is released at inflammatory sites. | Lactoferrin-family / human-bovine evidence | (pqac-00000005, pqac-00000010, pqac-00000011) |
| Core biochemical activity | Canonical lactoferrin binds **two Fe3+ ions reversibly**, remains iron-bound at unusually low pH, and shifts between apo/holo conformations; this supports iron sequestration, antioxidant protection, and iron-homeostasis functions. | Lactoferrin-family / human-bovine evidence | (pqac-00000006, pqac-00000007, pqac-00000009, pqac-00000011) |
| Core biochemical activity | Canonical lactoferrin exerts **antimicrobial activity** by depriving microbes of iron and by direct cationic interactions with negatively charged microbial surfaces such as LPS; N-terminal peptides (e.g., lactoferricin) can retain or enhance these effects. | Lactoferrin-family / human-bovine evidence | (pqac-00000005, pqac-00000006, pqac-00000007, pqac-00000010) |
| Immune signaling/pathways | Recent evidence places lactoferrin in **TLR4/TRAF6/IKK/IκB/NF-κB** signaling control: it can bind LPS, enter via LRP1, interfere with TRAF6 auto-ubiquitination, reduce IKKβ and p-IκB, and suppress NF-κB p65 with downstream cytokine lowering. | Primarily human/bovine and model-system evidence | (pqac-00000021, pqac-00000023, pqac-00000024, pqac-00000025) |
| Immune signaling/pathways | Antiviral pathways include **competition for host HSPGs/other receptors** and direct viral binding, reducing attachment/entry; additional receptor interactions reported for lactoferrin include LfR/LRP1, TLR4, DC-SIGN, CD14, CD206, nucleolin, and others. | Lactoferrin-family / human-bovine evidence | (pqac-00000006, pqac-00000007, pqac-00000009) |
| Vampire-bat-specific anticoagulant function | Historical biochemical work defines draculin as an **~88.5 kDa salivary glycoprotein anticoagulant** that inhibits activated **FIXa and FXa**; noncompetitive inhibition and immediate Xa–draculin complex formation were reported to block thrombin/fibrin generation during feeding. | Experimental in *D. rotundus* | (pqac-00000030, pqac-00000033, pqac-00000037, pqac-00000039) |
| Vampire-bat-specific anticoagulant function | Draculin anticoagulant activity is **strictly glycosylation-dependent**: active vs inactive draculin differ markedly in carbohydrate content/composition, and controlled chemical deglycosylation abolishes anti-Xa activity; lectin and glycan analyses support glycoform-specific function. | Experimental in *D. rotundus* | (pqac-00000029, pqac-00000030, pqac-00000031, pqac-00000032) |
| Vampire-bat-specific anticoagulant function | Important annotation caveat: although later omics studies place draculin on an LTF scaffold, the exact equivalence between the **biochemically defined anticoagulant draculin** and a canonical lactoferrin-like sequence remains somewhat unresolved because recombinant confirmation is limited and another major anticoagulant, **Desmolaris**, was later identified. | Mixed: *D. rotundus* experimental + interpretive caution | (pqac-00000003, pqac-00000036) |
| Proteolytic activity evidence | A 2024 review argues lactoferrin can **proteolytically degrade bacterial virulence factors**, adding to antimicrobial action, but emphasizes that the precise active site, substrates, and mechanism remain incompletely resolved. | Lactoferrin-family evidence; not directly shown in vampire bat | (pqac-00000005) |
| Applications/implementation 2023-2024 | Real-world lactoferrin use in 2023-2024 includes **infant formula/fortification, oral supplements, nutraceuticals, cosmetics, ocular delivery systems, microencapsulation/PEGylation, nanoparticles, and recombinant/synthetic production platforms** to meet demand and improve delivery. | Human/bovine implementation evidence | (pqac-00000044, pqac-00000046, pqac-00000048) |
| Applications/implementation 2023-2024 | Expert reviews portray lactoferrin as a promising **antimicrobial/antiviral adjunct** and possible alternative to some antibiotics, but emphasize that efficacy is **context-, formulation-, and dose-dependent** and that larger well-controlled trials are still needed, especially in COVID-19 and other inflammatory/infectious indications. | Expert consensus / recent reviews | (pqac-00000042, pqac-00000045, pqac-00000005, pqac-00000006) |
| Key quantitative data | 2024 meta-analysis of oral bovine lactoferrin vs ferrous sulfate for low hemoglobin found pooled benefit favoring lactoferrin: **SMD ~0.81 (95% CI 0.42–1.21, p<0.0001)**, but heterogeneity was very high (**I2=95.8%**), so certainty is limited. | Human clinical meta-analysis | (pqac-00000014, pqac-00000018, pqac-00000019) |
| Key quantitative data | 2024 preschool RCT: oral bovine lactoferrin **400 mg/day** for 4 months reduced median respiratory infection episodes by **50%** (1 vs 2), lowered odds of more infections (**OR 0.20, 95% CI 0.06–0.74, p=0.015**), shortened symptom duration (**3 vs 6 days**), and yielded **NNT = 4**; results are also visible in the retrieved figure/table images. | Human randomized controlled trial + retrieved figure/table image evidence | (pqac-00000015, pqac-00000017, pqac-00000020, pqac-00000040, pqac-00000041) |
| Key quantitative data | 2024 long-COVID double-blind RCT (**n=72**) found **no significant benefit** of lactoferrin over placebo for fatigue or other measured outcomes despite improvement in both arms, illustrating mixed translational evidence. | Human randomized controlled trial | (pqac-00000013) |
| Key quantitative data | 2023 NF-κB meta-analysis reported pooled decreases with lactoferrin exposure in inflammatory models: **TNF-α −8.73 pg/mL**, **IL-1β −2.21 pg/mL**, **IL-6 −3.24 pg/mL**; pathway markers also fell, including **NF-κB p65 3.88-fold**, **IKKβ 7.37-fold**, and **p-IκB 15.02-fold**. | Quantitative meta-analysis from experimental systems | (pqac-00000021, pqac-00000023, pqac-00000025) |


*Table: This table condenses the strongest evidence for the identity, function, localization, pathway context, and translational relevance of vampire-bat LTF/draculin. It distinguishes direct evidence from Desmodus rotundus studies from broader lactoferrin-family inference and includes recent quantitative clinical and meta-analytic findings.*