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Biomedical subjects

H Moise

Publications and source records attributed to H Moise.

9 recordsLinked to original sources

Chromatography of a Triton extracted beef cardiac cytochrome C1 preparation on diethylaminoethyl cellulose.

During the chromatography of a Triton X-100 extracted preparation of the mitochondrial membrane proteins on diethylaminoethyl cellulose, we have observed two chromatographic fractions containing cytochrome c1. One elutes from diethylaminoethyl cellulose with aqueous buffers alone, and the other elutes with those buffers after the addition of the nonionic detergent Triton X-100. The two forms occur in equimolar ratios and each retains its original chromatographic character on rechromatography, with no conversion of one form into the other.

Animals

Circular dichroism studies of the interaction of a limited hydrolysate of T4 gene 32 protein with T4 DNA and poly[d(A-T)].poly[d(A-T)].

gp32 I is a protein with a molecular weight of 27 000. It is obtained by limited hydrolysis of T4 gene 32 coded protein, which is one of the DNA melting proteins. gp32 I itself appears to be also a melting protein. It denatures poly[d(A-T)].poly[d(A-T)] and T4 DNA at temperatures far (50-60 degrees C) below their regular melting temperatures. Under similar conditions gp32 I will denature poly[d(A-T).poly[d(A-T)] at temperatures approximately 12 degrees C lower than those measured for the intact gp32 denaturation. For T4 DNA gp32 shows no melting behavior while gp32 I shows considerable denaturation (i.e., hyperchromicity) even at 1 degree C. In this paper the denaturation of poly[d(A-T)].poly[d(A-T)] and T4 DNA by gp32 I is studied by means of circular dichroism. It appears that gp32 I forms a complex with poly[d(A-T)]. The conformation of the polynucleotide in the complex is equal to that of one strand of the double-stranded polymer in 6 M LiCl. In the gp32 I DNA complex formed upon denaturation of T4 DNA, the single-stranded DNA molecule has the same conformation as one strand of the double-strand T4 DNA molecule in the C-DNA conformation.

Circular Dichroism

T4 gene 32 protein model for control of activity at replication fork.

Limited hydrolysis of gene 32 protein by various proteinases results in the production of three stable cleavage products. Two of these products show an affinity for native T4 DNA cellulose that the uncleaved protein does not exhibit. A model for proteolytic cleavage and for the total unwinding of DNA in advance of the replication fork is discussed in terms of this unusual binding affinity.

Binding Sites

Amino acid composition of proteins: Selection against the genetic code.

Distribution of amino acids in 68 representative proteins is compared with their distribution among 61 codons of the genetic code. Average amounts of lysine, aspartic acid, glutamic acid, and alanine are above the levels anticipated from the genetic code, and arginine, serine, leucine, cysteine, proline, and histidine are below such levels. Arginine plus lysine account for 11.0 percent of codons and aspartic acid plus glutamic acid account for 11.3 percent; thus the average charge is roughly neutral.

Amino Acid Sequence