Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.7.7 (DNA polymerase)
 17,007 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A modified assay of nick-translation of nuclei has been developed to study the chromatin structure of human beta-like globin genes in nuclei of K 562 cell line. Nuclei were gently digested with DNase I and nick-translated with E. coli DNA polymerase I in the presence of 32P-triphosphate nucleotides. The total DNA from the labelled nuclei was used as probes to hybridize restricted fragments of beta-like globin genes which have been immobilized on Diazobenzyloxymethyl (DBM) paper. Using this approach we have observed that in K 562 nuclei all beta-like globin genes, including epsilon, gamma, delta, and beta-globin genes and human 18 S ribosomal genes are preferentially labelled in comparison to alpha-lactalbumin and c-sis genes which do not express in K 562 cells, but the total DNA from nick-translated nuclei of a nonerythroid cell line hybridized none of those genes except for 18 S ribosomal gene. This assay is a simple and fast method for surveying chromatin structure of any individual DNA sequence in nuclei once the corresponding clone is available.
 ...
PMID:A study of the chromatin structure of human beta-like hemoglobin genes in K562 cell line with a modified assay of nick-translation of nuclei. 262 96

DNA replication was studied in vitro in the presence of native and esterified milk proteins [alpha-lactalbumin (ALA), beta-lactoglobulin (BLG) and beta-casein (BCN)]. Addition of unmodified proteins to the PCR medium did not change the result of the reaction seen by electrophoresis, even at excessive ratios of basic amino acids in proteins:phosphate groups in DNA as high as 100:1. Addition of esterified proteins greatly reduced the intensity of the bands corresponding to the newly synthesized DNA, at ratios as low as 1:1 and 5:1 in case of methylated-BLG and methylated-ALA, respectively. The inhibitory effect of esterified proteins was directly proportional to their extent of esterification and strongly related to their DNA-binding capacity. Generally, inhibition of PCR with esterified proteins was similar to what can be observed with histones. However, stronger inhibition was observed with highly esterified proteins when using a higher ratio of basic:acid residues (1:1) when compared with 0.5:1 ratio in case of histones. Highly esterified BCN did not exert any inhibitory effect because of its relatively lower pI when compared with that of other esterified milk proteins and due to its lower positive net charge at the pH used for PCR. During a second PCR run, only the addition of new DNA template was able to reinitiate the reaction, giving rise to new synthesized DNA. Addition of Taq DNA polymerase did not enhance DNA synthesis, showing that inhibition was performed only by binding of DNA template and not by the inhibition of the polymerase.
 ...
PMID:Esterified milk proteins inhibit DNA replication in vitro. 1171 22