What question did this study set out to answer?

Purify and characterize the structure and biochemical mechanism of actophorin, a novel actin-binding protein isolated from Acanthamoeba castellanii.

January 1, 1986Journal of Biological ChemistryOpen Access

Purification and characterization of actophorin, a new 15,000-dalton actin-binding protein from Acanthamoeba castellanii.

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Authors

JCJohn A. CooperNorthwestern University JBJ D BlumJohns Hopkins University RWR WilliamsUniversity of London

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Implication

Biochemical analysis reveals actophorin severs filaments and binds monomers in Acanthamoeba castellanii, indicating a calcium-independent mechanism of actin regulation.

Key Points

Purify and characterize the structure and biochemical mechanism of actophorin, a novel actin-binding protein isolated from Acanthamoeba castellanii.
Purified actophorin from Acanthamoeba castellanii cells and analyzed molecular weight, isoelectric point, amino acid composition, cellular concentration (0.4 ± 0.1 mg/g cells), and peptide maps.
Evaluated monomer binding, polymerization kinetics, filament shortening, and viscosity changes using pyrene fluorescence, viscometry, and analytical ultracentrifugation.
Actophorin is a distinct 15,000-Da polypeptide present at a roughly 10:1 cellular actin-to-actophorin molar ratio that lacks sequence homology or cross-reactivity with profilin, capping protein, or actin.
Actophorin inhibits filament elongation at both ends, accelerates late-stage spontaneous polymerization via fragmentation, and reduces actin filament length and low-shear viscosity in a Ca2+-independent manner across both muscle and amoeba actin.

Cite This Study

Cooper et al. (1986) studied this question.

synapsesocial.com/papers/6a0cd28259b087b0dc625dc2 https://doi.org/10.1016/s0021-9258(17)42495-1

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Implication

Biochemical analysis reveals actophorin severs filaments and binds monomers in Acanthamoeba castellanii, indicating a calcium-independent mechanism of actin regulation.

Purification and characterization of actophorin, a new 15,000-dalton actin-binding protein from Acanthamoeba castellanii.

Discussion

Member takes

Implication

Key Points

Cite This Study

Purification and characterization of actophorin, a new 15,000-dalton actin-binding protein from Acanthamoeba castellanii.

Discussion

Member takes

Implication

Key Points

Cite This Study

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