TNF molecules in a single amino acid replacement may be their biological activity toproduce different effects. When the mutagenesis human TNF-a following region ofamino acids (32,36,86,84,29,146,91), human TNF-a cytotoxic activity was significantly decreased, without changing its physical and chemical characteristics.Showed that the amino acids of these sites may be involved in human TNF-areceptor binding and start the human TNF-a mediated cytotoxic activity, is a veryimportant part of the people of TN Fa molecular structure.
the importance of the N-terminal of TNF molecules and the C-terminal
The absence of human TNF-a N-terminal amino acid test showed that the removal of the N-terminal seven amino acids may enhance its anti-tumor cytotoxic activity.Removal of eight amino acids, anti-tumor cytotoxic activity down to the samewild-type T NF. When the removal of more than 10 amino acids from the N-terminal,anti-tumor cytotoxic activity decreased significantly. The people of TN Fp in theremoval of the N-terminal 27 amino acids did not lose their cytotoxic activity.Prompted human TNF-a N-terminal nine amino acids and human TNF-p-N-terminal27 amino acids, though not required for its function, but in some ways can regulatethe biological activity of modified human TN Fa and TNF-p. In contrast, human TNF-a C-side of their biological activity is critical, may be part of the receptor binding site, when the removal of three amino acids of the C-terminal to its cytotoxic activity decreased significantly. The people of TNF-p in the removal of the C-terminal 10 amino acids can lead to the loss of its biological activity.
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