Structure and Function of a Pepstatin-Insensitive Acid Proteinase from Aspergillus Niger var. Macrosporus
The fungus Aspergillus niger var. macrosporus produces two extracellular acid proteinases, proteinases A and B.1–3 The acid proteinase B (Mr about 35 kDa) is sensitive to pepstatin, diazoacetyl-DL-norleucine methyl ester (DAN) and l,2-epoxy-3-(p-nitrophenoxy)propane (EPNP) and thus belongs to the ordinary aspartic proteinase family.4 On the other hand, the proteinase A (Mr about 22 kDa) is insensitive to pepstatin and also almost insensitive to DAN and EPNP,4 and shows substrate specificity fairly different from that of pepsin-type aspartic proteinases.5,6 These results indicate that the proteinase A belongs to a different acid proteinase family. This proteinase, therefore, seems to be an interesting object to investigate its structure/function relationships. Further, the study will contribute to a deeper understanding of the structure and function of the aspartic or acid proteinases in general.
KeywordsCircular Dichroism Aspergillus Niger Circular Dichroism Spectrum Aspartic Proteinase Acid Proteinase
Unable to display preview. Download preview PDF.
- 2.S. Horiuchi, M. Honjo, M. Yamasaki, and Y. Yamada, Studies on acid proteinases. I. Homogeneity and molecular weight of acid proteases from Aspergillus niger var. macrosporus (Proctase A and Proctase B), Sci.Pap. Coll. Gen. Educ. Univ. Tokyo 19: 127 (1969).Google Scholar
- 3.S. Horiuchi, M. Yamasaki, and Y. Yamada, Studies on acid proteases. II. Amino acid composition of acid proteases from Aspergillus niger var. macrosporus (“Proctases A and B”), Sci. Pap. Coll. Gen. Educ, Univ. Tokyo 19: 140 (1969)Google Scholar
- 4.W.-J. Chang, S. Horiuchi, K. Takahashi, M. Yamasaki, and Y. Yamada, The structure and function of acid proteases. IV. Effects of acid protease-specific inhibitors on the acid proteases from Aspergillus niger var. macrosporus, J. Biochem. 80: 975 (1976).Google Scholar
- 9.S. Murao and K. Oda, Pepstatin-insensitive acid proteinases, in: Aspartic Proteinases and Their Inhibitors, V. Kosíka, ed., pp. 379–399, Walter de Gruyter, Berlin (1985).Google Scholar
- 15.L. Szilagyi and O. Jardetzky, α-Proton chemical shifts and secondary structure in proteins, J. Magn. Reson. 83: 441 (1989).Google Scholar