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Study · In vitro (cell-free) · 1992

5 results

Thymosin beta 4 sequesters the majority of G-actin in resting human polymorphonuclear leukocytes.

Cassimeris L, Safer D, Nachmias VT, Zigmond SH

The Journal of cell biology1 Dec 1992Cited by 121 (Europe PMC)

PMID1447300 (opens in a new tab)PMCIDPMC2289708 (opens in a new tab)DOI10.1083/jcb.119.5.1261 (opens in a new tab)PepBankPUB-01447300
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Summary

The text of this summary is not shown here, because the article license does not allow reuse. Read it at the source (opens in a new tab)

Text rights: CC BY-NC. Results still quote short attributed sentences.

Results from this study5

1 result from studies that gave the peptide. No result from this study comes from people.

  1. 01LabIn vitro (cell-free)Activity measurement

    In vitro, the kinetics of bovine spleen thymosin beta‑4 binding to muscle pyrenyl G-actin were sufficiently rapid to accommodate the rapid changes in actin polymerization and depolymerization seen in vivo.

    In plain wordsIn lab tests, thymosin beta‑4 bound actin fast enough to match the quick actin changes seen in living cells.

    Peptide
    Thymosin beta-4 (human)
    Outcome
    Not applicableKinetics of thymosin beta 4 binding to G-actin
    Study

    n: not reported in source

    Bovine spleen thymosin beta 4 with muscle pyrenyl G-actin
    Outcome group
    Receptor activity and mechanism · Pharmacology
    Studied dose
    Dose not stated

    Source sentences

    Summary
    The kinetics of bovine spleen T beta 4 binding to muscle pyrenyl G-actin are sufficiently rapid to accommodate the rapid changes in actin polymerization and depolymerization observed in vivo in response to chemoattractant addition and removal.

Natural levels measured4

These results measure the body's own peptide. Nobody was given the peptide. They are not evidence about taking it. They are left out of key results, evidence counts and charts.

  1. 02LabEndogenous levelIn vitro (cells)Other

    Human PMNs contained approximately 169 fg thymosin beta‑4 per cell, corresponding to a cytoplasmic concentration of approximately 149 microM.

    In plain wordsHuman white blood cells (PMNs) hold large amounts of the body's own thymosin beta‑4.

    Peptide
    Thymosin beta-4 (human)
    Outcome
    Not applicableThymosin beta 4 content of human PMNs
    Study

    humann: not reported in source

    Human polymorphonuclear leukocytes (PMNs)
    Outcome group
    Immune response · Immune and inflammation

    Measurements

    Thymosin beta 4 content
    169 fg/cell
    human PMNs
    Cytoplasmic concentration
    149 microM
    human PMNs

    Source sentences

    Summary
    By reverse phase HPLC of perchloric acid supernatants, human PMNs contain approximately 169 fg/cell +/- 90 fg/cell (SD), corresponding to a cytoplasmic concentration of approximately 149 +/- 80.5 microM.

    This result measures the body's own Thymosin beta-4 (human). Nobody was given the peptide. It is not evidence about taking it.

  2. 03LabEndogenous levelIn vitro (cells)Mechanism

    In supernatants from resting human PMNs, a large fraction of G-actin had a mobility similar to the G-actin/thymosin beta‑4 complex.

    In plain wordsIn resting human white blood cells, much of the actin appeared to be bound to the body's own thymosin beta‑4.

    Peptide
    Thymosin beta-4 (human)
    Outcome
    Not applicableG-actin/thymosin beta 4 complex in resting PMNs
    Study

    humann: not reported in source

    Human polymorphonuclear leukocytes (PMNs)
    Outcome group
    Immune response · Immune and inflammation

    Source sentences

    Summary
    On non-denaturing polyacrylamide gels, a large fraction of G-actin in supernatants prepared from resting PMNs has a mobility similar to the G-actin/T beta 4 complex.

    This result measures the body's own Thymosin beta-4 (human). Nobody was given the peptide. It is not evidence about taking it.

  3. 04LabEndogenous levelIn vitro (cells)Mechanism

    Chemoattractant stimulation of human PMNs decreased the G-actin/thymosin beta‑4 complex.

    In plain wordsIn human white blood cells, a stimulating agent reduced the amount of actin bound to the body's own thymosin beta‑4.

    Peptide
    Thymosin beta-4 (human)
    Outcome
    DecreaseG-actin/thymosin beta 4 complex after chemoattractant stimulation
    Study

    humann: not reported in source

    Human polymorphonuclear leukocytes (PMNs)
    Outcome group
    Immune response · Immune and inflammation

    Source sentences

    Summary
    Chemoattractant stimulation of PMNs results in a decrease in this G-actin/T beta 4 complex.

    This result measures the body's own Thymosin beta-4 (human). Nobody was given the peptide. It is not evidence about taking it.

  4. 05LabEndogenous levelIn vitro (cells)Mechanism

    Pyrenyl actin polymerization was inhibited to a greater extent by supernatants from chemoattractant-stimulated PMNs than from resting PMNs, consistent with thymosin beta‑4 release as G-actin polymerizes.

    In plain wordsExtracts from stimulated human white blood cells blocked actin growth more than resting cells did, consistent with release of the body's own thymosin beta‑4.

    Peptide
    Thymosin beta-4 (human)
    Outcome
    IncreaseActin polymerization inhibition by supernatants from stimulated versus resting PMNs
    Study

    humann: not reported in source

    Human polymorphonuclear leukocytes (PMNs)
    Comparator
    Supernatants from resting PMNs
    Outcome group
    Immune response · Immune and inflammation

    Source sentences

    Summary
    Pyrenyl actin polymerization was inhibited to a greater extent in supernatants from stimulated cells and these results are qualitatively consistent with T beta 4 being released as G-actin polymerizes, with no chemoattractant-induced change in its affinity for G-actin.
    1 context sentence
    Summary · context
    To determine whether chemoattractant induced actin polymerization results from an inactivation of T beta 4, the G-actin sequestering activity of supernatants prepared from resting and chemoattractant stimulated cells was measured by comparing the rates of pyrenyl-actin polymerization from filament pointed ends.

    This result measures the body's own Thymosin beta-4 (human). Nobody was given the peptide. It is not evidence about taking it.

AI wrote and checked these results. AI can make mistakes, so check important results against the source.

Version history

PepBank keeps every version of the data on this study. Status changes from Retraction Watch, Europe PMC and Crossref are listed with their source.

  1. Version 2Current

    13 Oct 2026, 01:52 UTC

    Study results updated

  2. Version 1

    12 Oct 2026, 18:17 UTC

    First added · source update from Europe PMC

Subjects

Terms as the source lists them.

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