In POPC model membranes, natamycin slowed the motion of both ergosterol and cholesterol as assessed by deuterium NMR. This result cautions against treating every membrane interaction as exclusive to ergosterol. [2]
Arginine uptake inhibition with a substrate-retention control
Cell-based study · Saccharomyces cerevisiae cells; radiolabeled arginine uptake normalized to cell optical density [1]
Natamycin reduced arginine uptake across the tested concentration series. Addition after uptake had begun stopped further accumulation without a corresponding loss of previously accumulated arginine, supporting inhibition of import in this assay.
Literature-Reported Treatment Conditions
- Treatment concentration
- 0, 2, 5, 10, or 20 μM natamycin in Fig. 2A; 20 μM in Fig. 2B. The 30 μM arginine concentration is substrate, not drug potency.
- Exposure duration
- Fig. 2A: 5 min pretreatment, uptake followed through 10 min; Fig. 2B: natamycin added 8 min after substrate addition, follow-up through 20 min.
- Method
- Cellular radiotracer uptake; untreated and DMSO controls in Fig. 2A; untreated delayed-addition comparison in Fig. 2B.
- Vehicle
- DMSO control is identified in Fig. 2A; final vehicle percentage was not acquired.
- Reported limits
- SI Experimental Methods could not be retrieved. Exact yeast strain, supplier/lot, stock composition, final vehicle percentage and detailed assay buffer/temperature were not established from the acquired main-text scope; no values inferred.
Methods and source locations
Compound reported in the paper: Natamycin; Compound label in the paper: natamycin
Evidence applies to the reported natamycin material in this assay; it does not validate an Adooq lot, a salt conversion, or a clinical formulation.
Results, S. cerevisiae Can1p/arginine transport paragraph; Fig. 2A/B and caption; Experimental Methods, transport assays paragraph
14C-arginine uptake and retention after delayed drug addition: 30 μM tracer substrate; Fig. 2A pretreatment series and Fig. 2B delayed-addition control; means of three separately performed experiments with SD. — Results, S. cerevisiae Can1p/arginine transport paragraph; Fig. 2A/B and caption; Experimental Methods, transport assays paragraph
Sterol mobility in natamycin-containing model membranes
Biochemical assay · POPC membranes containing 20 mol% ergosterol-d1 or cholesterol-d1, with or without 10 mol% natamycin [2]
NMR spectra indicated slower sterol rotational motion in the presence of natamycin for both ergosterol and cholesterol. The comparable response under these conditions limits an interpretation of all membrane interactions as exclusive to ergosterol.
Literature-Reported Treatment Conditions
- Treatment concentration
- 10 mol% natamycin; 20 mol% deuterated sterol incorporated in POPC membranes (Fig. 1).
- Method
- Static 2H NMR of sterol-labeled model membranes, with matched no-natamycin membranes.
- Vehicle
- Natamycin and lipids mixed in methanol/chloroform; solvent evaporated and samples hydrated for NMR (§2.3).
- Reported limits
- Fig. 1 and the examined main NMR methods do not specify a replicate count or a treatment-to-acquisition interval.
Methods and source locations
Compound reported in the paper: Natamycin; Compound label in the paper: natamycin
Evidence applies to the reported natamycin material in this assay; it does not validate an Adooq lot, a salt conversion, or a clinical formulation.
Materials and methods §§2.1 and 2.3; Results §3.1, first NMR paragraphs; Fig. 1A/B and caption
2H NMR spectral changes reporting sterol motion: Static 2H NMR at 25 °C; matched membranes lacking natamycin; qualitative spectral comparison, not an affinity determination. — Materials and methods §§2.1 and 2.3; Results §3.1, first NMR paragraphs; Fig. 1A/B and caption
Lipid-dependent access of dithionite to membrane-associated fluorophore
Biochemical assay · NBD-PC-containing large unilamellar vesicles: POPC; POPC/cholesterol or POPC/ergosterol (4:1); POPC/SSM/cholesterol or POPC/SSM/ergosterol (4:1:1) [2]
Natamycin accelerated the slow fluorescence-quenching component in ergosterol-containing vesicles. Cholesterol-containing controls showed smaller effects, and the cholesterol/SSM mixture showed a decrease. The assay supports changes in lipid packing/accessibility; faster dithionite entry and faster NBD-PC transbilayer movement are alternative interpretations.
Literature-Reported Treatment Conditions
- Treatment concentration
- 3.3 μM natamycin, 33 μM lipid and 0.3 μM NBD-PC in the fluorescence measurement; lipid/natamycin molar ratio 10 (Fig. 5).
- Exposure duration
- Continuous traces; dithionite added 30 s after starting acquisition; Triton X-100 added after 300 s (§2.2).
- Method
- NBD-PC fluorescence measured at 37 °C; fitted slow quenching component compared across matched lipid compositions with and without embedded natamycin.
- Vehicle
- Natamycin dissolved in methanol and incorporated during vesicle preparation; final ethanol below 1% (v/v) (§2.2). Residual methanol concentration not specified in the examined method.
- Reported limits
- Fig. 5 caption says kP was normalized to no-natamycin values, while panel B labels kP in s−1 and shows paired conditions. Quantitative normalization/magnitude remains unclear; only direction is adopted.
Methods and source locations
Compound reported in the paper: Natamycin; Compound label in the paper: natamycin
Evidence applies to the reported natamycin material in this assay; it does not validate an Adooq lot, a salt conversion, or a clinical formulation.
Materials and methods §§2.1–2.2; Results §3.4; Fig. 5A/B and caption
Slow component of dithionite-induced NBD-PC fluorescence reduction: Bi-exponential fitting of fluorescence traces; matched vesicles without natamycin and detergent endpoint control. Caption reports mean ± SE from 1–2 independent samples, each measured in triplicate. No precise rates or fold changes adopted. — Materials and methods §§2.1–2.2; Results §3.4; Fig. 5A/B and caption
