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Study · In vitro (cell-free) · 1992

8 results

Interaction of thymosin beta 4 with muscle and platelet actin: implications for actin sequestration in resting platelets.

Weber A, Nachmias VT, Pennise CR, Pring M, Safer D

Biochemistry1 Jul 1992Cited by 129 (Europe PMC)

PMID1627561 (opens in a new tab)DOI10.1021/bi00142a002 (opens in a new tab)PepBankPUB-01627561
Publisher pagePubMedAsk about this study
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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: Publisher copyright. Results still quote short attributed sentences.

Results from this study8

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

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

    Thymosin beta‑4 formed a 1:1 complex with monomeric actin under physiological salt conditions.

    In plain wordsIn lab tests, thymosin beta‑4 bound one actin monomer at a time under conditions like those in cells.

    Peptide
    Thymosin beta-4 (human)
    Outcome
    Not applicableComplex formation of thymosin beta 4 with monomeric actin
    Study

    n: not reported in source

    Purified actin in vitro
    Outcome group
    Receptor activity and mechanism · Pharmacology
    Studied dose
    Dose not stated

    Source sentences

    Summary
    T beta 4 forms a 1:1 complex with monomeric actin under physiological salt conditions.
  2. 02LabIn vitro (cell-free)Activity measurement

    The Kd of thymosin beta‑4 for actin was not affected by calcium.

    In plain wordsIn lab tests, calcium did not change how tightly thymosin beta‑4 binds actin.

    Peptide
    Thymosin beta-4 (human)
    Outcome
    No significant changeEffect of calcium on thymosin beta 4 affinity for actin
    Study

    n: not reported in source

    Purified actin in vitro
    Outcome group
    Receptor activity and mechanism · Pharmacology
    Studied dose
    Dose not stated

    Source sentences

    Summary
    Its Kd for actin is not affected by calcium.
  3. 03LabIn vitro (cell-free)Activity measurement

    Thymosin beta‑4 bound only to actin monomers and not to filament ends or alongside the filament.

    In plain wordsIn lab tests, thymosin beta‑4 bound only single actin monomers, not actin filament ends or sides.

    Peptide
    Thymosin beta-4 (human)
    Outcome
    Not applicableBinding of thymosin beta 4 to actin monomers versus filaments
    Study

    n: not reported in source

    Purified actin in vitro
    Outcome group
    Receptor activity and mechanism · Pharmacology
    Studied dose
    Dose not stated

    Source sentences

    Summary
    T beta 4 binds only to actin monomers and not to filament ends or alongside the filament.
  4. 04LabIn vitro (cell-free)Activity measurement

    Thymosin beta‑4-actin complexes did not elongate actin filaments at either the barbed or the pointed end.

    In plain wordsIn lab tests, thymosin beta‑4-actin complexes did not lengthen actin filaments at either end.

    Peptide
    Thymosin beta-4 (human)
    Outcome
    No significant changeFilament elongation by thymosin beta 4-actin complexes
    Study

    n: not reported in source

    Purified actin in vitro
    Outcome group
    Receptor activity and mechanism · Pharmacology
    Studied dose
    Dose not stated

    Source sentences

    Summary
    T beta 4-actin complexes do not elongate actin filaments at either the barbed or the pointed end
  5. 05LabIn vitro (cell-free)Activity measurement

    Unlike actobindin, thymosin beta‑4 did not specifically suppress the nucleation of actin polymerization.

    In plain wordsIn lab tests, unlike actobindin, thymosin beta‑4 did not specifically block the start of actin polymerization.

    Peptide
    Thymosin beta-4 (human)
    Outcome
    No significant changeSuppression of actin polymerization nucleation
    Study

    n: not reported in source

    Purified actin in vitro
    Comparator
    Actobindin
    Outcome group
    Receptor activity and mechanism · Pharmacology
    Studied dose
    Dose not stated

    Source sentences

    Summary
    unlike actobindin, T beta 4 does not specifically suppress the nucleation of polymerization.
  6. 06LabIn vitro (cell-free)Activity measurement

    The Kd of thymosin beta‑4 for platelet actin was 0.4-0.7 microM.

    In plain wordsIn lab tests, thymosin beta‑4 bound platelet actin with a Kd of 0.4-0.7 microM.

    Peptide
    Thymosin beta-4 (human)
    Outcome
    Not applicableKd of thymosin beta 4 for platelet actin
    Study

    n: not reported in source

    Purified actin in vitro
    Outcome group
    Receptor activity and mechanism · Pharmacology
    Studied dose
    Dose not stated

    Measurements

    Kd
    0.4 to 0.7 µM
    platelet actin

    Source sentences

    Summary
    its Kd of 0.4-0.7 microM for platelet actin, which had been prepared by a newly devised simpler method, and (b) the values for the concentrations of monomeric actin and of T beta 4 which we measured as 280 and 560 microM, respectively.

Natural levels measured2

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. 07LabEndogenous levelEx vivo tissueOther

    In resting platelets, the measured concentrations of monomeric actin and thymosin beta‑4 were 280 and 560 microM, respectively.

    In plain wordsIn resting platelets, the body's own thymosin beta‑4 was measured at 560 microM, with monomeric actin at 280 microM.

    Peptide
    Thymosin beta-4 (human)
    Outcome
    Not applicableMeasured monomeric actin and thymosin beta 4 concentrations in resting platelets
    Study

    n: not reported in source

    Resting platelets
    Outcome group
    Receptor activity and mechanism · Pharmacology

    Measurements

    monomeric actin concentration
    280 µM
    resting platelets
    thymosin beta 4 concentration
    560 µM
    resting platelets

    Source sentences

    Summary
    the values for the concentrations of monomeric actin and of T beta 4 which we measured as 280 and 560 microM, respectively.

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

  2. 08LabEndogenous levelEx vivo tissueMechanism

    Using a Kd of 0.7 microM, the thymosin beta‑4-complexed actin in platelets was calculated at 70 to 240 microM, depending on the free G-actin concentration.

    In plain wordsCalculated from lab values, the body's own thymosin beta‑4 in platelets would hold between 70 and 240 microM of actin.

    Peptide
    Thymosin beta-4 (human)
    Outcome
    Not applicableCalculated thymosin beta 4-complexed actin in platelets
    Study

    n: not reported in source

    Calculation from in vitro Kd and measured platelet concentrations
    Outcome group
    Receptor activity and mechanism · Pharmacology

    Measurements

    thymosin beta 4-complexed actin
    70 to 240 µM
    calculated, Kd 0.7 microM

    Source sentences

    Summary
    Using the higher Kd value of 0.7 microM, the T beta 4-complexed actin is calculated to be between 70 and 240 microM, depending on the steady-state free G-actin concentration.

    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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