Showing papers by "Paul Doty published in 1978"

Construction and characterization of a 2.5-kilobase procollagen clone

Abstract: Recombinant bacterial plasmids have been constructed by inserting double-stranded chicken procollagen cDNA sequences linked to chemically synthesized decanucleotides containing HindIII sites into the HindIII site of pBR322. After transformation of Escherichia coli chi1776, colonies were selected by ampicillin resistance and recombinants containing procollagen sequences were identified by colony hybridization to 32P-labeled procollagen cDNA. The inserts from three recombinant plasmids, pCg10, pCg13, and pCg45, were 1200, 2200, and 2550 base pairs long respectively. Their sequence homology has been established by restriction mapping and crosshybridization of nick-translated plasmids to Southern blots of Hpa II fragments of the inserts, pCg45 has been positively identified as containing the pro alpha2 collagen sequence by partial determination of the DNA sequence of its ends: it has a short thymine-rich sequence at one end and a sequence coding for residues 478--499 in the chicken alpha2 chain at the other end.

Characterization of the histone core complex

Abstract: A stable histone core complex containing equimolar ratios of H2A, H2B, H3, and H4 has been isolated from chicken erythrocyte chromatin in high salt. This complex has been characterized by sedimentation and chemical cross-linking studies. In velocity ultracentrifugation, only one single sharp sedimentation boundary has been observed with sedimentation coefficient S020,w = 3.8 +/- 0.1. The molecular weight of the histone core complex has been investigated by low-speed sedimentation equilibrium studies over a wide range of protein concentration. Analysis of the apparent weight-average molecular weight as a function of concentration indicates that the histone core complex in 2 M NaCl, pH 9.0, is in equilibrium between a tetramer (H2A)(H2B)(H3)(H4) and an octamer [(H2A)(H2B)(H3)(H4)]2 species with a tetramer molecular weight of 55,000. The equilibrium constant K is approximately 1.2 X 10(-5) liter per mol at 10 degrees. Evidence of such a tetramer-octamer equilibrium in solution is also supported by the results of our chemical crosslinking experiments on the histone core complex.

Arms Control Enters the Gray Area

Abstract: If a Strategic ArmsLimitation Treaty is reached and ratified, ceilings and subceilings will have been placed on the number of launchers from which the U.S. and the U.S.S.R. could attack each other over intercontinental distances. If the SALT process is then to continue, the reductions in such ceilings and subceilings becomes an obvious goal of further negotiations. Since both national leaders have endorsed reductions in numbers on numerous occasions,’ it is even more likely that this will be a central feature of negotiations when they resume after SALT 11. Yet, progress in reductions could be an illusion if at least a start is not made in bringing weapons of lesser range under control. These are the gray area weapons that can reach targets 400 to 2,000 miles or more distant from the point of launch. For the most part these weapons are concentrated in Europe and the western military districts of the Soviet Union. These gray area weapons unconstrained by either SALT2 or MBFR3 consist of a wide array of medium bombers, fighter-