Journal article
Differential behavior of gizzard isoactins
Archives of biochemistry and biophysics, Vol.210(2), pp.598-608
1981
DOI: 10.1016/0003-9861(81)90226-5
PMID: 7305348
Abstract
Turkey gizzard smooth muscle myofibrils, the actin of which is composed of 75% smooth muscle γ-isoactin and 25% nonmuscle β-isoactin, were separated into an actomyosin and a cytoskeletal fraction. Isoelectric focusing analysis of the actomyosin actin showed it was 80% γ-isoactin and 20% β-isoactin. It thus appears that the major actin in the tissue is also the major form involved in force generation. When the cytoskeletal material was extracted with low-ionic-strength solution for 18 h at 4 °C, the actin released was 95% γ and 5% β compared with the 75:25 ratio found in the original cytoskeletal material. The extracted material revealed the presence of F-actin filaments and high-molecular-weight aggregates. Little of the material was in a low-molecular-weight form. On the other hand, extraction of the cytoskeletal material with 0.6
m KI resulted in the two isoactins being extracted in the same proportions in which they were found in the original cytoskeletal material. However, when this KI-extracted material was subsequently chromatographed on Bio-Gel A-5m equilibrated with 0.6
m KCl, the γ-isoactin migrated predominantly as a very high molecular weight form while the β-isomer moved in the lower-molecular-weight range of the elution profile. This aggregation behavior displayed by the γ-isoactin was not observed with the γ-isoactin in the actomyosin fraction. These results show that the two gizzard isoactins in the cytoskeletal residue behave very differently in response to various extraction media, and are consistent with possible differential isoactin utilization in gizzard smooth muscle.
Details
- Title: Subtitle
- Differential behavior of gizzard isoactins
- Creators
- Peter A Rubenstein - Biochemistry Department, University of Iowa, Iowa City, Iowa 52242 USA
- Resource Type
- Journal article
- Publication Details
- Archives of biochemistry and biophysics, Vol.210(2), pp.598-608
- Publisher
- Elsevier Inc
- DOI
- 10.1016/0003-9861(81)90226-5
- PMID
- 7305348
- ISSN
- 0003-9861
- eISSN
- 1096-0384
- Language
- English
- Date published
- 1981
- Academic Unit
- Stead Family Department of Pediatrics; Biochemistry and Molecular Biology; Internal Medicine
- Record Identifier
- 9984025393702771
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