Singh, Jagmohan and Rao, Satyanarayana and Manchanalli, R (1987) Chromatin organization of sonication-resistant spermatid nuclei of rat testes. In: Indian Journal of Biochemistry & Biophysics, 24 (4). pp. 181-188.Full text not available from this repository. (Request a copy)
Sonication-resistant spermatid (SRS) nuclei isolated from rat testes contain basic proteins TP, TP2, and S1 with trace amts. of histones TH1 (Hla and Hlt), H2A, H3, and negligible amts. of histones H2B and H4. Digestion of SRS-nuclei with micrococcal nuclease showed that only 10% of the DNA was made acid-sol. while the rest (90%) of the DNA underwent random endonucleolytic nicks. Dithiothreitol (100 mM) did not increase the accessibility of SRS-nuclei towards micrococcal nuclease. On the other hand, digestion of SRS-nuclei with TPCK-treated trypsin showed that the major proteins TP, TP2, and S1 are completely accessible to enzyme digestion. Digestion with chymotrypsin resulted in 4 chymotryptic fragments, F1-F4. By comparing the digestion pattern of SRS-nuclei and protein TP, fragments F1 and F4 were found to be derived from TP. Studies on the salt extractability of the various basic proteins of SRS-nuclei showed that the proteins TP, TP2, and histones were quant. extd. at salt concns. of 0.4-0.8M NaCl while protein S1 was not extd., even at 1.2M NaCl. Based on the CD spectrum of protein TP as well as secondary structure considerations based on Chou and Fasman rules, it is concluded that protein TP has predominantly random coiled structure facilitating its max. interaction with DNA.
|Item Type:||Journal Article|
|Additional Information:||Copyright belongs to National Institute of Science Communication and Information Resources|
|Department/Centre:||Division of Biological Sciences > Biochemistry|
|Date Deposited:||07 Mar 2008|
|Last Modified:||27 Aug 2008 13:13|
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