Factors influencing regeneration of soybean from mature and immature cotyledons

Soybean (Glycine max L.) plantlets were e?ciently regenerated from mature and immature cotyledons of?ve different genotypes by studying various parameters affecting regeneration. Green organogenic noduleswere induced at the proximal end, which subsequently differentiated into shoot buds on modi?ed MS(Murashige T. and Skoog F. 1962. Physiol. Plant. 15: 473-497) medium. The presence of 6-benzylaminopurine(BAP) and thidiazuron (TDZ) in the medium exerted a synergistic effect, in that regenerationeffciency was higher than for either cytokin alone. The regenerated shoot buds elongated and rooted onMS medium containing 0.29 lM gibberellic acid (GA3) and 2.69 lM a-naphthaleneaceticacid (NAA),respectively. Rooted plants were established in the greenhouse with 87% success and produced viable seeds.Preliminary studies with Agrobacterium show great promise for soybean transformation based on theregeneration protocol reported here.     

Effects of carbohydrate removal on the structure and activity of bovine lutropin

Bovine lutropin was successfully deglycosylated by treatment with anhydrous HF at 0°C for 60 min. The overall loss of carbohydrate residues was about 70%. Fucose, mannose and galactosamine residues were removed completely. About six residues of N-acetylglucosamine were left in the deglycosylated hormone. This degree of deglycosylation did not reduce receptor binding ability but in vitro biological activity was completely lost. Consistent with these properties, the deglycosylated lutropin inhibited the in vitro biological action of the native lutropin. The results demonstrate that the full complement of carbohydrate residues including the sulfated hexosamines are not required for receptor binding but they are necessary to impart appropriate conformational features necessary for activation of the target cells.     

The primary structure of ovine interstitial cell stimulating hormone. IV: Disulfide bridges of the beta subunit.

The disulfide linkage of the 12 half-cystine residues in the beta subunit of ovine interstitial cell stimulating hormone has been investigated by enzymic and partial acid hydrolysis of the intact molecule. Results indicate that the disulfide bridges are formed by residues 9-38, 23-72, 26-110, 34-90, 57-88, and 93-100.     

The primary structure of ovine interstitial cell-stimulating hormone III: Disulfide bridges of the α-subunit

The disulfide linkage of the ten half-cystine residues in the α-subunit of ovine interstitial cell-stimulating hormone has been investigated by partial acid and enzymic hydrolysis of the intact molecule. Results indicate that the disulfide bridges are formed by residues 14–86, 11–64, 35–63, 32–89, and 36–91.     

Enteroendocrine cells sense bacterial tryptophan catabolites to activate enteric and vagal neuronal pathways

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