Biomaterial Database

Myosin binding to actin. Structural analysis using myosin fragments. 1987

L Castellani, and B W Elliott, and D A Winkelmann, and P Vibert, and C Cohen

Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, MA 02254.

The actin-binding property of the myosin head 20 K (K = 10(3) Mr) fragment has been examined by a structural assay. A new fragment is produced by digestion of scallop myosin synthetic filaments with a lysine-specific protease. This fragment consists of the rod together with two "nubs" corresponding to the 20 K fragment, which retain both the regulatory and essential light chains. Myosin filaments, digested for different lengths of time, were mixed with F-actin and visualized by electron microscopy after negative staining. When the head is cleaved, but the head fragments remain associated, the filaments bind actin in an ATP-sensitive manner. Filaments made primarily of the nub-containing fragments, however, bind actin very poorly. In addition, electron microscopic characterization of actin-binding by the isolated tryptic 20 K fragment from chicken myosin indicates that binding of this fragment to actin is probably non-specific. These results suggest that interactions between the 20 K region and the other peptides in the head are essential for actin-binding.

UI	MeSH Term	Description	Entries
D008854	Microscopy, Electron	Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.	Electron Microscopy
D009218	Myosins	A diverse superfamily of proteins that function as translocating proteins. They share the common characteristics of being able to bind ACTINS and hydrolyze MgATP. Myosins generally consist of heavy chains which are involved in locomotion, and light chains which are involved in regulation. Within the structure of myosin heavy chain are three domains: the head, the neck and the tail. The head region of the heavy chain contains the actin binding domain and MgATPase domain which provides energy for locomotion. The neck region is involved in binding the light-chains. The tail region provides the anchoring point that maintains the position of the heavy chain. The superfamily of myosins is organized into structural classes based upon the type and arrangement of the subunits they contain.	Myosin ATPase,ATPase, Actin-Activated,ATPase, Actomyosin,ATPase, Myosin,Actin-Activated ATPase,Actomyosin ATPase,Actomyosin Adenosinetriphosphatase,Adenosine Triphosphatase, Myosin,Adenosinetriphosphatase, Actomyosin,Adenosinetriphosphatase, Myosin,Myosin,Myosin Adenosinetriphosphatase,ATPase, Actin Activated,Actin Activated ATPase,Myosin Adenosine Triphosphatase
D010446	Peptide Fragments	Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.	Peptide Fragment,Fragment, Peptide,Fragments, Peptide
D000199	Actins	Filamentous proteins that are the main constituent of the thin filaments of muscle fibers. The filaments (known also as filamentous or F-actin) can be dissociated into their globular subunits; each subunit is composed of a single polypeptide 375 amino acids long. This is known as globular or G-actin. In conjunction with MYOSINS, actin is responsible for the contraction and relaxation of muscle.	F-Actin,G-Actin,Actin,Isoactin,N-Actin,alpha-Actin,alpha-Isoactin,beta-Actin,gamma-Actin,F Actin,G Actin,N Actin,alpha Actin,alpha Isoactin,beta Actin,gamma Actin
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D015879	Myosin Subfragments	Parts of the myosin molecule resulting from cleavage by proteolytic enzymes (PAPAIN; TRYPSIN; or CHYMOTRYPSIN) at well-localized regions. Study of these isolated fragments helps to delineate the functional roles of different parts of myosin. Two of the most common subfragments are myosin S-1 and myosin S-2. S-1 contains the heads of the heavy chains plus the light chains and S-2 contains part of the double-stranded, alpha-helical, heavy chain tail (myosin rod).	Actomyosin Subfragments,Meromyosin Subfragments,Myosin Rod,Myosin S-1,Myosin S-2,ATPase, Actin-S1,Actin S1 ATPase,Actoheavy Meromyosin,Actomyosin Subfragment 1 ATPase,H-Meromyosin,Heavy Meromyosin,Heavy Meromyosin Subfragment-1,Heavy Meromyosin Subfragment-2,Light Meromyosin,Myosin Subfragment-1,Myosin Subfragment-2,ATPase, Actin S1,Actin-S1 ATPase,H Meromyosin,Heavy Meromyosin Subfragment 1,Heavy Meromyosin Subfragment 2,Meromyosin Subfragment-1, Heavy,Meromyosin Subfragment-2, Heavy,Meromyosin, Actoheavy,Meromyosin, Heavy,Meromyosin, Light,Myosin S 1,Myosin S 2,Myosin Subfragment 1,Myosin Subfragment 2,Subfragment-1, Heavy Meromyosin,Subfragment-1, Myosin,Subfragment-2, Heavy Meromyosin,Subfragment-2, Myosin,Subfragments, Actomyosin,Subfragments, Meromyosin,Subfragments, Myosin