Judith Saide

Boston University | BU · Department of Physiology and Biophysics

The Z-band is an electron dense structure that borders sarcomeres in striated muscle. It is a complex assembly of proteins that organizes and stabilizes both thick and thin filament arrays in the contractile apparatus. By anchoring actin filaments and protein extensions of myosin filaments, the Z-band ensures that active as well as passive tensions...

Insect indirect flight muscles (IFM) contain a third filament system made up of elastic connecting or C-filaments. The giant protein projectin is the main, if not the only, component of these structures. In this study we found that projectin is oriented within the IFM sarcomere with its NH2-terminus embedded in the Z-bands. We demonstrate that this...

Stretchin-klp is a newly described protein in Drosophila indirect flight muscles (IFM) that migrates on SDS gels as two distinct components of approximately 225 and 231 kD. Although the larger isoform is IFM specific, the smaller stretchin-klp isoform is expressed not only in IFM, but also in wild-type tissues of the adult head, abdomen and thorax...

Wild-type and mutant thin filaments were isolated directly from "myosinless" Drosophila indirect flight muscles to study the structural basis of muscle regulation genetically. Negatively stained filaments showed tropomyosin with periodically arranged troponin complexes in electron micrographs. Three-dimensional helical reconstruction of wild-type f...

In Drosophila, the large muscle protein, projectin, has very different localizations in synchronous and asynchronous muscles, suggesting that projectin has different functions in different muscle types. The multiple projectin isoforms are encoded by a single gene; however they differ significantly in size (as detected by gel mobility) and show diff...

The indirect flight muscles of Drosophila are adapted for rapid oscillatory movements which depend on properties of the contractile apparatus itself. Flight muscles are stretch activated and the frequency of contraction in these muscles is independent of the rate of nerve impulses. Little is known about the molecular basis of these adaptations. We...

Monoclonal antibodies raised against four proteins from insect asynchronous flight muscle have been used to characterize the cross-reacting proteins in synchronous muscle of Drosophila melanogaster. Two proteins, alpha-actinin and Z(400/600), are found at the Z-band of every muscle examined. A larger variant of alpha-actinin is specific for the per...

Monoclonal antibodies (mAb's) have been raised against proteins in preparations of Z-discs isolated from honeybee fibrillar flight muscle. These antibodies have identified four Z-disc antigens on immunoblots of honeybee fibrillar proteins. Antibody α binds to the 90–100 kD protein,α-actinin; mAb P interacts with the protein, projectin, an extremely...

Twelve monoclonal antibodies have been raised against proteins in preparations of Z-disks isolated from Drosophila melanogaster flight muscle. The monoclonal antibodies that recognized Z-band components were identified by immunofluorescence microscopy of flight muscle myofibrils. These antibodies have identified three Z-disk antigens on immunoblots...

Twelve monoclonal antibodies have been raised against proteins in preparations of Z-disks isolated from Drosophila melanogaster flight muscle. The monoclonal antibodies that recognized Z-band components were identified by immunofluorescence microscopy of flight muscle myofibrils. These antibodies have identified three Z-disk antigens on immunoblots...

A major component on sodium dodecyl sulfate-containing gels of solubilized isolated Z-discs, purified from honeybee flight muscle, migrates with an apparent molecular weight of 360,000. Antibodies to this high molecular weight polypeptide have been prepared by injecting rabbits with homogenized gel slices containing the protein band. With indirect...

Recent studies from this laboratory have shown that nerve growth factor (NGF) is secreted by many diverse types of cells in culture, including fibroblasts, L cells, muscle cells, and certain tumor cells. Further, studies of the molecular properties of cell-secreted NGF (Pantazis, N. J., et al. (1977) Biochemistry 16, 1525; Murphy, R. A., et al. (19...

Rat skeletal muscle cells and a cloned myogenic cell line synthesize and secrete in culture a molecule that is immunologically and biologically indistinguishable from the active form of nerve growth factor (NGF) from mouse submandibular gland. This protein can be detected in medium conditioned by muscle cells both before and after fusion and in the...

The fine structure of Z-discs from frog, chameleon, rabbit, rat and human muscles was studied. Our data lead us to conclude that the basket-weave (woven) lattice represents the fundamental en face pattern of the vertebrate Z-disc, regardless of the manner of fixation, and we suggest that the large and small-“square” lattices are fixation artifacts....

Some molecular properties of the nerve growth factor (NGF) secreted in mouse saliva and that present in submandibular glands have been measured for comparison with previously studied forms of NGF. The results show that mouse saliva contains two biologically active NGF species. One has a molecular weight near 114,000, and the other, a molecular weig...

The concept that the salivary gland of the mouse is an endocrine organ for nerve growth factor (NGF) has been reexamined. Serum concentrations of the protein have been measured by radioimmunoassay in male and female mice and in mice from which the submandibular glands were removed. In spite of the fact that the submandibular glands of male mice con...

Sedimentation and gel-filtration studies of mouse submandibular gland 7S-nerve growth factor (NGF) reveal that this complex dissociates to yield its components at concentrations much higher than those required to exhibit biological activity. Results further indicate that the alpha and gamma protein c omponents of the 7S-NGF complex probably play no...

Bacteriophage immunoassays, radioimmunoassays, and biologic assays have been used to measure levels of the nerve growth factor (NGF) in media conditioned by rat C 6 glioma cells in culture. By all three criteria, these cells secrete a macromolecule which is indistinguishable from mouse submandibular gland NGF. It should be noted that the C 6 glioma...

Nerve growth factor (NGF) is a protein composed of two identical chains of mass 13,259. An analysis of the sedimentation equilibrium, sedimentation velocity, and gel filtration behavior of dilute solutions of NGF indicates the existence of a rapidly reversible monomer in equilibrium dimer equilibrium and that the association constant K for the reac...

In the preceding chapter, Bradshaw et al. have summarized much of the historical background information arising from the discovery of and early studies on nerve growth factor (NGF) by Bueker and by Levi-Montalcini, Hamburger and their colleagues. Here we should only like to draw attention to a brief list of those historical aspects which are most p...

Z-discs have been isolated from honeybee indirect flight muscle fibers with 0.43% lactic acid, and have been purified with differential and sucrose density-gradient centrifugation. In the light microscope, isolated Z-discs are pale, round, homogeneous structures with diameters ranging from 2 μm to 9 μm, depending on the nature of the suspending med...

Z-discs from the dorsal longitudinal indirect flight muscles of the honeybee (Apis mellifera) are perforated with hundreds of triangular-shaped tubes ordered into an hexagonal array. Each tube is surrounded by 80 Å thick rims which incorporate six thin filaments, three from each bordering sarcomere. Although the triangular rims of the tubes are ori...

Thesis--Boston University, 1972. Includes bibliographical references (leaves 172-186).

Thesis--Boston University. Bibliography: p. 172-185.