Purification and characterisation of growth hormone from water buffaloes (Bubalus bubalis)

Lactogenic hormones from the pituitaries of Indian water buffaloes have been purified and characterised with a longer goal of understanding and manipulating milk yields in this species because of its importance in rural economy. Freshly frozen pituitaries were subjected either directly to the protocol of Spitsberg or to the protocol of Ellis. In the latter case the side fraction 'extract-C was then subjected to the protocol of Spitsberg. Growth hormone was monitored through purification steps by a heterologous RIA using anti-sheep growth hormone antibodies. Growth hormone was purified to 'homogeneity' and in good yield i.e. 250 mg/kg of frozen glands. Buffalo growth hormone exhibited a molecular mass of 22 kDa and had methionine as its N-terminus amino acid. It exhibited microheterogeneity in terms of size, charge and hydrophobicity. Less than 2% of the preparation was found to be glycosylated. It showed presence of one mole of tryptophan/mole of the hormone. Antibodies to buffalo growth hormone raised in rabbits cross-reacted with ovine growth hormone but were free of anti-prolactin antibodies. Homologous RIA and ELISA for buffalo growth hormone have been developed.