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S E Rudnick

Publications and source records attributed to S E Rudnick.

8 recordsLinked to original sources
PubMed1994

Comparison of the utility of capillary zone electrophoresis and high-performance liquid chromatography in peptide mapping and separation.

Capillary zone electrophoresis (CZE) and high-performance liquid chromatography (HPLC) have been used in the analysis of the primary structure of recombinant human insulin-like growth factor I (rhIGF-I). CZE both complements and supplements HPLC separations. CZE has been used to resolve peaks which co-elute on HPLC, as well as to help establish the identity of tryptic fragments in peptide mapping experiments.

Amino Acid Sequence↗
PubMed1993

Protein and peptide mobility in capillary zone electrophoresis. A comparison of existing models and further analysis.

Capillary zone electrophoresis of peptide fragments from the tryptic digest of human recombinant insulin-like growth factor I (rhIGF-I) has been carried out and the observed mobilities used to compare the relative applicability of existing mobility models. In addition, the physical forces affecting electromigration have been systematically analyzed in order to more accurately describe the physical chemistry involved. Such an approach should further improve the ability to predict electrophoretic mobility in capillary zone electrophoresis.

Amino Acid Sequence↗
PubMed1989

Regulation of vertebrate striated muscle contraction.

Most current textbooks of cell biology and histology use the steric blocking model to describe the protein mechanism by which vertebrate striated muscle contraction is regulated. Evidence accumulated in the past decade, however, reveals the regulation of muscle contraction to be far more complex than this model predicts.

Actins↗
PubMed1986

Effect of DNAase I on muscle tropomyosin polymerization.

DNAase I, an endonuclease which interacts with G-actin, also affects tropomyosin polymerization. With chicken pectoralis or bovine cardiac ventricle tropomyosin, DNAase I both prevents tropomyosin from polymerizing and disrupts already formed tropomysin filaments. DNAase I and filament tropomyosin can also form a precipitable complex. In the electron microscope, the complex is observed as irregularly margined stellate-shaped structures with a maximum size of 9 micron. Isolated DNAase I-tropomyosin stellate complex consists of a 2:1 molar ratio of DNAase I and tropomyosin, suggesting that each tropomyosin subunit can bind DNAase I.

Animals↗
PubMed1986

Inhibition of muscle tropomyosin polymerization by DNAse I.

Tropomyosin polymerization is inhibited by DNAse I, an endonuclease which also interacts with G-actin. A 1:4 molar ratio of DNAse I to adult chicken pectoralis muscle tropomyosin almost completely prevents the increased viscosity of tropomyosin under polymerizing ionic conditions. While G-actin binding to DNAse I inhibits the DNAse I hydrolysis of DNA, tropomyosin does not affect this enzymatic activity. G-actin-DNAse I interaction is also not altered by tropomyosin.

Actins↗
PubMed1980

Calmodulin, S-100, and crayfish sarcoplasmic calcium-binding protein crystals suitable for X-ray diffraction studies.

We have grown crystals of calmodulin, of S-100, and crayfish sarcoplasmic calcium-binding protein and are now determining their structures by x-ray diffraction. The sarcoplasmic calcium-binding protein crystallizes from 50% 2-methyl-2,4-pentanediol in space group P2(1)2(1)2(1) with unit cell dimensions of 58.9, 68.5, and 116.1 A, and diffracts beyond 3.0 A Bragg spacing. S-100 crystallized from 15% polyethylene glycol 6000 in space group P4(1) with unit cell dimensions of 56.0, 56.0, and 112.8 A, and diffracts beyond 3.0 A. Calmodulin crystallized from 15% polyethylene glycol in space group P2(1) with unit cell dimensions of 61.8, 56.7, and 40.0 A, beta = 92.7 degrees, and diffracts beyond 5.0 A.

Animals↗
PubMedDate not supplied

Crystal structure of calmodulin.

The crystal structure of calmodulin has been determined to 3.6 A resolution. At this resolution the polypeptide chain can be traced. Some of the side chains have tentatively been identified. Refinement of the structure with x-ray diffraction data measured to 1.65 A resolution is continuing. As reported by Babu et al. calmodulin is about 65 A long and 30 A in diameter. Homolog domains 1 and 2 are related by a local twofold axis, as in parvalbumin and in troponin C, and form one end of the molecule. Domains 3 and 4 form the other end. The second alpha-helix of domain 2 and a short interdomain region are continuous with the first helix of domain 3, thereby forming a single helix from residues 67-93. The central region, residues 75-84, of this long helix forms a handle connecting the two pairs of homolog domains. Exclusive of the residues, 75-84, in the handle the closet approach of side chains of pair 1, 2 to pair 3, 4 is 12 A. The spatial relationship of pair 1, 2 to pair 3, 4 is similar in calmodulin to the relationship of the corresponding pairs in troponin C. However, in troponin C there are three additional residues in the handle region of the long alpha-helix and the two pairs are about 5.0 A further apart. On the surface of pair 1, 2 in calmodulin there is one extended region with many hydrophobic side chains from both domain 1 and domain 2. This hydrophobic patch is bounded by two distinct clusters of anionic side chains, one from the beginning of the first helix of domain 1 and on the other side of the hydrophobic surface one from the beginning of the first helix of domain 2. Homologously, the hydrophobic patch on the surface of pair 3, 4 is bounded by two clusters of aspartate and glutamate residues. Either or both of these hydrophobic surfaces may be sites to which calmodulin target proteins bind.

Amino Acid Sequence↗