{'fraction_non_alphanumeric': 0.02490726020137785, 'fraction_numerical': 0.018018018018018018, 'mean_word_length': 5.231023102310231, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Structure-Function Studies in Parathyroid Hormone

Most studies of parathyroid hormone have been with hormone of bovine origin. The amino acid sequence (Fig 1) of this has recently been determined (Niall et al. 1970, Brewer & Ronan 1970). The amino terminal sequence of the first 34 residues has been synthesized (Potts et al. 1971). This synthetic peptide has been shown to be biologically active and to react with antisera produced against the native hormone. Human parathyroid hormone has been shown immunologically to differ from bovine parathyroid (O'Riordan et al. 1969). Though the human hormone has only been isolated in microgram quantities, its amino acid composition has been shown to differ from that of bovine parathyroid hormone, especially by containing three residues of threonine which is absent from the bovine hormone (O'Riordan et al. 1971). Recently, porcine parathyroid hormone has been isolated (Woodhead et al. 1971) and has been shown to differ immunologically both from bovine and from human parathyroid hormones (Woodhead & O'Riordan 1971). These differences were shown in a radioimmunoassay system with antisera against bovine parathyroid hormone and 125I-labelled bovine parathyroid hormone. When labelled porcine parathyroid hormone instead was used in this system the hormone from the three species behaved similarly. It seems likely that with labelled porcine parathyroid hormone, the behaviour of immunologically active similar parts of the molecules is being monitored and that with labelled bovine hormone and antisera against bovine parathyroid hormone, the behaviour of parts of the molecules that differ is being monitored. The amino acid composition of porcine parathyroid hormone differs from bovine parathyroid hormone in five respects. There is one fewer residue of aspartic acid, of alanine, and of phenyl alanine. There is one (rather than two