1
|
Telek E, Karádi K, Kardos J, Kengyel A, Fekete Z, Halász H, Nyitrai M, Bugyi B, Lukács A. The C-terminal tail extension of myosin 16 acts as a molten globule, including intrinsically disordered regions, and interacts with the N-terminal ankyrin. J Biol Chem 2021; 297:100716. [PMID: 33930467 PMCID: PMC8253979 DOI: 10.1016/j.jbc.2021.100716] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 04/19/2021] [Accepted: 04/26/2021] [Indexed: 11/20/2022] Open
Abstract
The lesser-known unconventional myosin 16 protein is essential in proper neuronal functioning and has been implicated in cell cycle regulation. Its longer Myo16b isoform contains a C-terminal tail extension (Myo16Tail), which has been shown to play a role in the neuronal phosphoinositide 3-kinase signaling pathway. Myo16Tail mediates the actin cytoskeleton remodeling, downregulates the actin dynamics at the postsynaptic site of dendritic spines, and is involved in the organization of the presynaptic axon terminals. However, the functional and structural features of this C-terminal tail extension are not well known. Here, we report the purification and biophysical characterization of the Myo16Tail by bioinformatics, fluorescence spectroscopy, and CD. Our results revealed that the Myo16Tail is functionally active and interacts with the N-terminal ankyrin domain of myosin 16, suggesting an intramolecular binding between the C and N termini of Myo16 as an autoregulatory mechanism involving backfolding of the motor domain. In addition, the Myo16Tail possesses high structural flexibility and a solvent-exposed hydrophobic core, indicating the largely unstructured, intrinsically disordered nature of this protein region. Some secondary structure elements were also observed, indicating that the Myo16Tail likely adopts a molten globule-like structure. These structural features imply that the Myo16Tail may function as a flexible display site particularly relevant in post-translational modifications, regulatory functions such as backfolding, and phosphoinositide 3-kinase signaling.
Collapse
Affiliation(s)
- Elek Telek
- Department of Biophysics, Medical School, University of Pécs, Pécs, Hungary; MTA-PTE Nuclear-Mitochondrial Interactions Research Group, Pécs, Hungary
| | - Kristóf Karádi
- Department of Biophysics, Medical School, University of Pécs, Pécs, Hungary; Szentágothai Research Center, Pécs, Hungary
| | - József Kardos
- Department of Biochemistry, Institute of Biology, Eötvös Loránd University, Budapest, Hungary
| | - András Kengyel
- Department of Biophysics, Medical School, University of Pécs, Pécs, Hungary; MTA-PTE Nuclear-Mitochondrial Interactions Research Group, Pécs, Hungary; Szentágothai Research Center, Pécs, Hungary
| | - Zsuzsanna Fekete
- Department of Biophysics, Medical School, University of Pécs, Pécs, Hungary
| | - Henriett Halász
- Department of Biophysics, Medical School, University of Pécs, Pécs, Hungary; MTA-PTE Nuclear-Mitochondrial Interactions Research Group, Pécs, Hungary
| | - Miklós Nyitrai
- Department of Biophysics, Medical School, University of Pécs, Pécs, Hungary; MTA-PTE Nuclear-Mitochondrial Interactions Research Group, Pécs, Hungary; Szentágothai Research Center, Pécs, Hungary
| | - Beáta Bugyi
- Department of Biophysics, Medical School, University of Pécs, Pécs, Hungary; Szentágothai Research Center, Pécs, Hungary.
| | - András Lukács
- Department of Biophysics, Medical School, University of Pécs, Pécs, Hungary; MTA-PTE Nuclear-Mitochondrial Interactions Research Group, Pécs, Hungary; Szentágothai Research Center, Pécs, Hungary.
| |
Collapse
|
2
|
Yang X, Lv C, Zhang S, Zhao G, Ma C. Zn2+ rather than Ca2+ or Mg2+ used as a cofactor in non-muscular actin from the oyster to control protein polymerization. Biochim Biophys Acta Gen Subj 2013; 1830:4179-88. [DOI: 10.1016/j.bbagen.2013.04.030] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Revised: 04/04/2013] [Accepted: 04/23/2013] [Indexed: 11/25/2022]
|
3
|
Altschuler GM, Willison KR. Development of free-energy-based models for chaperonin containing TCP-1 mediated folding of actin. J R Soc Interface 2009; 5:1391-408. [PMID: 18708324 DOI: 10.1098/rsif.2008.0185] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
A free-energy-based approach is used to describe the mechanism through which chaperonin-containing TCP-1 (CCT) folds the filament-forming cytoskeletal protein actin, which is one of its primary substrates. The experimental observations on the actin folding and unfolding pathways are collated and then re-examined from this perspective, allowing us to determine the position of the CCT intervention on the actin free-energy folding landscape. The essential role for CCT in actin folding is to provide a free-energy contribution from its ATP cycle, which drives actin to fold from a stable, trapped intermediate I3, to a less stable but now productive folding intermediate I2. We develop two hypothetical mechanisms for actin folding founded upon concepts established for the bacterial type I chaperonin GroEL and extend them to the much more complex CCT system of eukaryotes. A new model is presented in which CCT facilitates free-energy transfer through direct coupling of the nucleotide hydrolysis cycle to the phases of actin substrate maturation.
Collapse
Affiliation(s)
- Gabriel M Altschuler
- Cancer Research UK Centre for Cell and Molecular Biology, Chester Beatty Laboratories, Institute of Cancer Research, 237 Fulham Road, London SW3 6JB, UK
| | | |
Collapse
|
4
|
Zhang Y, Ji B, Ling P, Zhang T. Trehalose and hyaluronic acid coordinately stabilized freeze-dried pancreatic kininogenase. Eur J Pharm Biopharm 2007; 65:18-25. [PMID: 16950608 DOI: 10.1016/j.ejpb.2006.07.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2006] [Revised: 07/06/2006] [Accepted: 07/07/2006] [Indexed: 11/26/2022]
Abstract
The ability and mechanisms of stabilization of freeze-dried formulations of pancreatic kininogenase (PKase) by carbohydrates were evaluated. Activity and structure of PKase were examined after freeze-drying and rehydration in presence with or without a carbohydrate. Addition of trehalose, lactose, sucrose, hyaluronic acid (HA) or a combination of trehalose and HA to PKase formulations prior to freeze-drying step increases the stability of PKase during freeze-drying, storage and rehydration as measured by activity preservation. The combination of trehalose and HA is the most effective for the stabilization of PKase. Addition of HA alone to a formulation does not affect protein structure, but it increases glass-transition temperature (Tg) and stability of lyophilized PKase in presence of trehalose during dehydration, storage and rehydration processes. Therefore, trehalose and HA offer complementary properties that improve the stability of PKase during dehydration, storage and rehydration.
Collapse
Affiliation(s)
- Yuhua Zhang
- College of Food Science & Nutritional Engineering, China Agricultural University, Beijing, China
| | | | | | | |
Collapse
|
5
|
Altschuler GM, Klug DR, Willison KR. Unfolding energetics of G-alpha-actin: a discrete intermediate can be re-folded to the native state by CCT. J Mol Biol 2005; 353:385-96. [PMID: 16171816 DOI: 10.1016/j.jmb.2005.07.062] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2005] [Revised: 07/22/2005] [Accepted: 07/25/2005] [Indexed: 11/16/2022]
Abstract
Nascent actin requires interactions with the highly conserved and essential eukaryotic chaperonin-containing TCP-1 (CCT) for its correct folding to the native state in vivo. Biochemical and structural analysis of the interaction between actin and CCT has been studied extensively but the underlying energetics and kinetics of the CCT-dependent actin folding process are not understood. We investigated the unfolding and folding pathways of actin, using stopped flow fluorescence and biochemical techniques. By using very low concentrations of actin, taking account of temperature and ATP concentration dependences we were able to determine accurately the activation energy of unfolding to a stable intermediate, I(3). Use of the fluorescent calcium chelator Quin-2 and consideration of the ATP concentration dependence on the unfolding rate has allowed the intrinsic kinetics to be linked to the accepted reaction scheme for actin denaturation. A free energy of -28.7(+/-0.2) kJ mol(-1) was determined for the loss of ATP from Ca-free G-actin, in good agreement with previous studies. Understanding the K(eq) value for this step then allowed the temperature dependence of the unfolding reaction of co-factor-free actin to be evaluated, yielding an activation energy for the unfolding of G-actin of 81.3(+/-3.3) kJ mol(-1). By chemical coupling of the extrinsic probe, Alexa Fluor 488 to cysteine 374 of native alpha-actin, we were able to follow the binding and folding of I(3) by CCT, observing for the first time, in vitro re-folding of EDTA-denatured G-actin. The high value of the activation energy between native actin and a non-native folding intermediate (I(3)) is characteristic of a partially folded, molten globule state expected to contain partial secondary structure.
Collapse
Affiliation(s)
- Gabriel M Altschuler
- Cancer Research UK, Centre for Cell and Molecular Biology, Chester Beatty Laboratories, Institute of Cancer Research, 237 Fulham Road, London SW3 6JB, UK
| | | | | |
Collapse
|
6
|
Hemung BO, Yongsawatdigul J. Ca2+Affects Physicochemical and Conformational Changes of Threadfin Bream Myosin and Actin in a Setting Model. J Food Sci 2005. [DOI: 10.1111/j.1365-2621.2005.tb11500.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
7
|
Kuznetsova IM, Turoverov KK, Uversky VN. Use of the Phase Diagram Method to Analyze the Protein Unfolding-Refolding Reactions: Fishing Out the “Invisible” Intermediates. J Proteome Res 2004; 3:485-94. [PMID: 15253430 DOI: 10.1021/pr034094y] [Citation(s) in RCA: 116] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Partially folded conformations are important players in protein self-organization, function, and misfolding, thus attracting the intensive and constant attention of researchers. Different conformational states of proteins can be easily discriminated from one another using the multiparametric approach, which usually involves the application of several physicochemical methods sensitive to the various structural levels of a protein molecule. This approach gives the most complete information about the structural changes in protein during its de- and renaturation. However, in many cases researches are interested in a brief and simple test for the appearance of an intermediate state. The binding of the hydrophobic fluorescent probe ANS represents one of the well-established techniques, allowing the retrieval of such information. We are introducing another approach, based on the analysis of the spectroscopic data in a form of spectral diagrams. The essence of this method is to build the Ilambda1, versus Ilambda2 dependence, where Ilambda1 and Ilambda2 are the spectral intensity values (e.g., fluorescence, CD, FTIR, absorbance, etc.) measured on wavelengths lambda1 and lambda2. We are showing that this approach gives the detailed description of the protein unfolding pathway, detects the numerous partially folded species, and even fishes out the hidden intermediates. An application of this method for the analysis of the equilibrium and kinetic unfolding/refolding of several proteins under the variety of conditions is described. Advantages and disadvantages of the technique suggested are also discussed.
Collapse
Affiliation(s)
- Irina M Kuznetsova
- Institute of Cytology, Russian Academy of Sciences, 194064 St. Petersburg, Russia
| | | | | |
Collapse
|
8
|
Allison SD, Manning MC, Randolph TW, Middleton K, Davis A, Carpenter JF. Optimization of storage stability of lyophilized actin using combinations of disaccharides and dextran. J Pharm Sci 2000; 89:199-214. [PMID: 10688749 DOI: 10.1002/(sici)1520-6017(200002)89:2<199::aid-jps7>3.0.co;2-b] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The storage stability of a dry protein depends on the structure of the dried protein, as well as on the storage temperature relative to the glass transition temperature of the dried preparation. Disaccharides are known to preserve the native conformation of a dried protein; however, the resulting T(g) of the sample may be too low ensure adequate storage stability. On the other hand, formulations dried with high molecular weight carbohydrates, such as dextran, have higher glass transition temperatures, but fail to preserve native protein conformation. We tested the hypothesis that optimizing both protein structure and T(g) by freeze-drying actin with mixtures of disaccharides and dextran would result in increased storage stability compared to actin dried with either disaccharide or dextran alone. Protein structure in the dried solid was analyzed immediately after lyophilization and after storage at elevated temperatures with infrared spectroscopy, and after rehydration by infrared and circular dichroism spectroscopy. Structural results were related to the polymerization activity recovered after rehydration. Degradation was noted with storage for formulations containing either sucrose, trehalose, or dextran alone. Slight increases in T(g) observed in trehalose formulations compared to sucrose formulations did not result in appreciable increases in storage stability. Addition of dextran to sucrose or trehalose increased formulation T(g) without affecting the capacity of the sugar to inhibit protein unfolding during lyophilization and resulted in improved storage stability. Also, dextran provides an excellent amorphous bulking agent, which can be lyophilized rapidly with formation of strong, elegant cake structure. These results suggest that the strategy of using a mixture of disaccharide and polymeric carbohydrates can optimize protein storage stability.
Collapse
Affiliation(s)
- S D Allison
- University of Colorado Center for Pharmaceutical Biotechnology, Denver, Colorado 80262, USA
| | | | | | | | | | | |
Collapse
|
9
|
Schüler H, Lindberg U, Schutt CE, Karlsson R. Thermal unfolding of G-actin monitored with the DNase I-inhibition assay stabilities of actin isoforms. EUROPEAN JOURNAL OF BIOCHEMISTRY 2000; 267:476-86. [PMID: 10632717 DOI: 10.1046/j.1432-1327.2000.01023.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Actin is one of the proteins that rely on chaperonins for proper folding. This paper shows that the thermal unfolding of G-actin, as studied by CD and ultraviolet difference spectrometry, coincides with a loss in DNase I-inhibiting activity of the protein. Thus, the DNase I inhibition assay should be useful for systematic studies of actin unfolding and refolding. Using this assay, we have investigated how the thermal stability of actin is affected by either Ca2 + or Mg2 + at the high affinity divalent cation binding site, by the concentration of excess nucleotide, and by the nucleotide in different states of phosphorylation (ATP, ADP.Pi, ADP. Vi, ADP.AlF4, ADP.BeFx, and ADP). Actin isoforms from different species were also compared, and the effect of profilin on the thermal stability of actin was studied. We conclude that the thermal unfolding of G-actin is a three-state process, in which an equilibrium exists between native actin with bound nucleotide and an intermediate free of nucleotide. Actins in the Mg-form were less stable than the Ca-forms, and the stability of the different isoforms decreased in the following order: rabbit skeletal muscle alpha-actin = bovine cytoplasmic gamma-actin > yeast actin > cytoplasmic beta-actin. The activation energies for the thermal unfolding reactions were in the range 200-290 kJ.mol- 1, depending on the bound ligands. Generally, the stability of the actin depended on the degree with which the nucleotide contributed to the connectivity between the two domains of the protein.
Collapse
Affiliation(s)
- H Schüler
- Department of Cell Biology, The Wenner-Gren Institute, Stockholm University, Sweden
| | | | | | | |
Collapse
|
10
|
Kuznetsova IM, Biktashev AG, Khaitlina SY, Vassilenko KS, Turoverov KK, Uversky VN. Effect of self-association on the structural organization of partially folded proteins: inactivated actin. Biophys J 1999; 77:2788-800. [PMID: 10545377 PMCID: PMC1300551 DOI: 10.1016/s0006-3495(99)77111-0] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The propensity to associate or aggregate is one of the characteristic properties of many nonnative proteins. The aggregation of proteins is responsible for a number of human diseases and is a significant problem in biotechnology. Despite this, little is currently known about the effect of self-association on the structural properties and conformational stability of partially folded protein molecules. G-actin is shown to form equilibrium unfolding intermediate in the vicinity of 1.5 M guanidinium chloride (GdmCl). Refolding from the GdmCl unfolded state is terminated at the stage of formation of the same intermediate state. An analogous form, known as inactivated actin, can be obtained by heat treatment, or at moderate urea concentration, or by the release of Ca(2+). In all cases actin forms specific associates comprising partially folded protein molecules. The structural properties and conformational stability of inactivated actin were studied over a wide range of protein concentrations, and it was established that the process of self-association is rather specific. We have also shown that inactivated actin, being denatured, is characterized by a relatively rigid microenvironment of aromatic residues and exhibits a considerable limitation in the internal mobility of tryptophans. This means that specific self-association can play an important structure-forming role for the partially folded protein molecules.
Collapse
Affiliation(s)
- I M Kuznetsova
- Institute of Cytology, Russian Academy of Sciences, 194064 St. Petersburg, Russia
| | | | | | | | | | | |
Collapse
|
11
|
Allison SD, Randolph TW, Manning MC, Middleton K, Davis A, Carpenter JF. Effects of drying methods and additives on structure and function of actin: mechanisms of dehydration-induced damage and its inhibition. Arch Biochem Biophys 1998; 358:171-81. [PMID: 9750178 DOI: 10.1006/abbi.1998.0832] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Limited stability impedes the development of industrial and pharmaceutical proteins. Dried formulations are theoretically more stable, but the drying process itself causes structural damage leading to loss of activity after rehydration. Lyophilization is the most common method used to dry proteins, but involves freezing and dehydration, which are both damaging to protein. We compared an air-drying method to freeze-drying to test the hypothesis that terminal dehydration is the critical stress leading to loss of activity. The secondary structure of air-dried and freeze-dried actin was analyzed by infrared spectroscopy and related to the level of activity recovered from the rehydrated samples. Actin dried by either method in the absence of stabilizers was highly unfolded and the capacity to polymerize was lost upon rehydration. The degree of unfolding was reduced by air-drying or freeze-drying actin with sucrose, and the level of activity recovered upon rehydration increased. The addition of dextran to sucrose improved the recovery of activity from freeze-dried, but not air-dried samples. Dextran alone failed to protect the structure and function of actin dried by either method, indicating that proteins are not protected from dehydration-induced damage by formation of a glassy matrix. In some cases, recovered activity did not correlate directly with the level of structural protection conferred by a particular additive. This result suggests that secondary structural protection during drying is a necessary but not sufficient condition for the recovery of activity from a dried protein after rehydration.
Collapse
Affiliation(s)
- S D Allison
- School of Pharmacy, University of Colorado Health Sciences Center, Denver, Colorado, 80262, USA
| | | | | | | | | | | |
Collapse
|
12
|
Bettache N, Bertrand R, Kassab R. Maleimidobenzoyl-G-actin: structural properties and interaction with skeletal myosin subfragment-1. Biochemistry 1990; 29:9085-91. [PMID: 2271579 DOI: 10.1021/bi00490a028] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
We have investigated various structural and interaction properties of maleimidobenzoyl-G-actin (MBS-actin), a new, internally cross-linked G-actin derivative that does not exhibit, at moderate protein concentration, the salt--and myosin subfragment 1 (S-1)-induced polymerizations of G-actin and reacts reversibly and covalently in solution with S-1 at or near the F-actin binding region of the heavy chain (Bettache, N., Bertrand, R., & Kassab, R. (1989) Proc. Natl. Acad. Sci. U.S.A. 86, 6028-6032). The far-ultraviolet CD spectrum and alpha-helix content of the MBS-actin were identical with those displayed by native G-actin. 45Ca2+ measurements showed the same content of tightly bound Ca2+ in MBS-actin as in G-actin and the EDTA treatment of the modified protein promoted the same red shift of the intrinsic fluorescence spectrum as observed with native G-actin. Incubation of concentrated MBS-actin solutions with 100 mM KCl + 5 mM MgCl2 led to the polymerization of the actin derivative when the critical monomer concentration reached 1.6 mg/mL, at 25 degrees C, pH 8.0. The MBS-F-actin formed activated the Mg2(+)-ATPase of S-1 to the same extent as native F-actin. The MBS-G-actin exhibited a DNase I inhibitor activity very close to that found with native G-actin and was not to be at all affected by its specific covalent conjugation to S-1.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
Affiliation(s)
- N Bettache
- Centre de Recherches de Biochimie Macromoléculaire du CNRS, INSERM U249, Université de Montpellier I, France
| | | | | |
Collapse
|
13
|
Strzelecka-Gołaszewska H, Zmorzynski S, Mossakowska M. Effects of various amino acid replacements on the conformational stability of G-actin. EUROPEAN JOURNAL OF BIOCHEMISTRY 1985; 147:331-42. [PMID: 3918865 DOI: 10.1111/j.1432-1033.1985.tb08754.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Circular dichroic spectra of native, EDTA-treated and heat-denatured G-actin from chicken gizzard smooth muscle are virtually the same as those of rabbit skeletal muscle actin. The rates of changes produced by EDTA or heat in the secondary structure are, however, higher in the case of gizzard actin. Similar differences were found in the rates of inactivation as measured by loss of polymerizability during incubation with EDTA or Dowex 50. The results are explicable in terms of local differences in the conformation at specific site(s) important for maintaining the native state of actin monomer. Involvement of the ATP binding site was shown by measuring the equilibrium constant for the binding of ATP to the two actins. Difference in the conformation of some additional site(s) is indicated by a higher rate constant of inactivation of nucleotide-free actin observed for gizzard actin. No significant difference was found in the equilibrium constant for the binding of Ca2+ at the single high-affinity site in gizzard and skeletal muscle actin. Comparison of inactivation kinetics of actin from chicken gizzard, rabbit skeletal, bovine aorta, and bovine cardiac muscle suggests that the amino acid replacements Val-17----Cys-17 and/or Thr-89----Ser-89 have a destabilizing effect on the native conformation of G-actin. The results indicate that deletion of the acidic residue at position 1 of the amino acid sequence has no effect on the conformation of the ATP binding site and the high-affinity site for divalent cation as well.
Collapse
|
14
|
Huang CK, Hill JM, Bormann BJ, Mackin WM, Becker EL. The photoaffinity probe 8-N3[alpha-32P]ATP labels the ATP-binding sites of rabbit neutrophil and skeletal muscle actin. FEBS Lett 1983; 159:145-9. [PMID: 6688227 DOI: 10.1016/0014-5793(83)80434-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
8-Azido-[alpha-32P]ATP (8-N3-ATP) was used as a photoaffinity label for ATP binding sites in the subcellular fractions of rabbit peritoneal neutrophils. The radioactive 8-N3-ATP was specifically incorporated into one major protein of 43 kDa. The isoelectric point, molecular mass and subcellular distribution of this labeled protein closely resemble those of the actin. 8-N3-[alpha-32P]ATP was further tested as a photoaffinity label for the ATP binding site in the purified rabbit skeletal muscle G-actin. The radioactive 8-N3-ATP was specifically incorporated into the actin band in SDS-polyacrylamide gel. The results indicate that 8-N3-ATP can be used as a photoaffinity label for actin.
Collapse
|
15
|
Changes in actin lysine reactivities during polymerization detected using a competitive labeling method. J Biol Chem 1982. [DOI: 10.1016/s0021-9258(18)33549-x] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
|
16
|
Curmi PM, Barden JA, dos Remedios CG. Conformational studies of G-actin containing bound lanthanide. EUROPEAN JOURNAL OF BIOCHEMISTRY 1982; 122:239-44. [PMID: 7060574 DOI: 10.1111/j.1432-1033.1982.tb05872.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The presence of bound Ln ions gives rise to changes in the ultraviolet absorbance of G-actin. Previously, Ln ions have been shown to mobilize the adenosine moiety of ATP bound to the actin monomer. The changes in ultraviolet absorbance appear to be fully attributable to this mobilization. Any structural changes induced in G-actin by the substitution of Ln ions for Ca2+ must be small enough so as not to perturb the environment of any aromatic chromophores other than those exposed by the mobility of the nucleotide. This conclusion is supported by measurements of the rates of proteolytic digestion of actin with and without bound Ln ions. The effect of Ln ions on the actin-bound nucleotide is not simply due to the increase in positive charge on the actin monomer. This is demonstrated by the absence of any ultraviolet spectral changes on the addition of a fivefold excess of Ca2+. Analysis of the ultraviolet difference spectrum obtained when Ln ions bind to G-actin indicates that at least one tryptophan residue is partially exposed to the solvent coincident with mobilization of the nucleotide. Tb3+ luminescence enhancement studies indicate that there are no Trp, Tyr or Phe residues in the vicinity of the high-affinity cation site. These results suggest that the exposed Trp may be close to the nucleotide.
Collapse
|
17
|
Johnson P, Blazyk JM. Involvement of an arginine residue of actin in tropomyosin binding. Biochem Biophys Res Commun 1978; 82:1013-8. [PMID: 151536 DOI: 10.1016/0006-291x(78)90884-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
|
18
|
Paulsen G. (32P) phosphate incorporation into ATP during ATP hydrolysis and its dependence on the interaction of actin and myosin. EUROPEAN JOURNAL OF BIOCHEMISTRY 1976; 61:77-80. [PMID: 812702 DOI: 10.1111/j.1432-1033.1976.tb09999.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The incorporation of 32Pi into ATP has been found to be catalyzed by myosin only when and if it interacts with actin. This exchange reaction is inhibited in natural but not in desensitized actomyosin after removing of trace Ca2+ with ethyleneglycol bis(2-aminoethyl)-N,N'-tetraacetic acid (EGTA). In desensitized as well as in synthetic actomyosin the exchange reaction can be fully inhibited by the addition of troponin I (0.5 mg troponin I/mg actomyosin results in a 50% inhibition) or after replacing the Mg activator by CaCl2. The exchange rate is about 1:500 of the ATPase rate in presence of 2 mM phosphate. These results suggest the existence of an 'energy-rich' actin -- myosin -- nucleoside-diphosphate intermediate during the cross-bridge cycle.
Collapse
|
19
|
Strzelecka-Golaszewska H, Nagy B, Gergely J. Changes in conformation and nucleotide binding of Ca, Mn, or MgG-actin upon removal of the bound divalent cation. Studies of ultraviolet difference spectra and optical rotation. Arch Biochem Biophys 1974; 161:559-69. [PMID: 4209137 DOI: 10.1016/0003-9861(74)90339-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
20
|
Ikemoto N, Nagy B, Bhatnagar GM, Gergely J. Studies on a Metal-binding Protein of the Sarcoplasmic Reticulum. J Biol Chem 1974. [DOI: 10.1016/s0021-9258(19)42738-5] [Citation(s) in RCA: 90] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
|
21
|
Strzelecka-Golaszewska H. Effect of tightly bound divalent cation on the equilibria between G-actin-bound and free ATP. EUROPEAN JOURNAL OF BIOCHEMISTRY 1973; 37:434-40. [PMID: 4777250 DOI: 10.1111/j.1432-1033.1973.tb03003.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
|