Abstract
The composition of milk has been reviewed by Jenness (1). It is an extremely complex mixture of components, consisting of water, lipids, carbohydrates, proteins, salts and many miscellaneous compounds. The largest component is water. The lipids are 98% triglycerides, mostly as globules. Carbohydrate is mainly as lactose. There are several classes of proteins. The largest group (80%) are phosphoproteins called “caseins”. They are associated with calcium in “casein micelles”, which are 20–300 μn in diameter. The α1s-, α s2-, β- and κ-caseins are in the ratio 3: 0.8: 3: 1. The other milk proteins are called “whey proteins” and include β-lactoglobulin, α-lactalbumin, blood serum albumin and immunoglobulins. In total there are probably about 105 kinds of molecules in milk.
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References
R. Jenness, Composition of Milk, In: Fundamentals of Dairy Chemistry, N.R Wong, ed., Van Nostrand Reinhold Co., New York, 1–38 (1988).
R.J. Brown & C.A. Ernstrom, Milk-Clotting Enzymes and Cheese Chemistry, Part I--Milk-Clotting Enzymes, In: Fundamentals of Dairy Chemistry, N.R Wong, ed., Van Nostrand Reinhold Co., New York, 609–633 (1988).
K. Arima, S. Iwasaki & G. Tamura, Milk clotting enzyme from microorganisms Part I. Screening test and the identification of the potent fungus, Agr. Biol Chem., 31:540–545 (1967).
D.B. Hyslop, A.M. Swanson & D.B. Lund, Heat inactivation of milk clotting enzymes at different pH hydrogen-ion concentration, Mucor miehei, Mucor pusillus proteases, and rennet and rennet-pepsin, J. Dairy Sei., 62:1227–1232 (1979).
T. Yamashita, S. Higashi, T. Higashi, H. Machida, S. Iwasaki, M. Nishiyama, & T. Beppu, Mutation of a fungal aspartic proteinase, Mucor pusillus renin, to decrease thermal stability for use as a milk coagulant, J. Biotech., 32:17–28 (1994).
W.S. Rickert & RA. McBride-Warren, Structural and functional determinants of Mucor miehei protease. III, isolation and composition of the carbohydrate moiety, Biochim. Biophys. Acta, 336:437–444 (1974).
S. Branner-Jorgensen, P. Eigtved & P. Schneider, Reduced thermostability of modified Mucor rennet, Neth. Milk and Dairy J., 35: 361–364 (1981).
S. Branner-Jorgensen, P. Schneider & P. Eigtved, A method of modifying the thermal destabilization of microbial rennet and a method of cheese making using rennet so modified, U.K. Pat. Appl. 2,045,772A (1980).
D.A. Cornelius, Process for decreasing the thermal stability of microbial rennet, U.S. Pat 4,348,482 (1982).
A. Goldman, How to make my blood boil, Structure, 3:1277–1279.
E.D. Brown & R.Y. Yada, A kinetic and equilibrium study of the denaturation of aspartic proteinases from fungi, Endothia parasitica and Mucor miehei, Biochemica et Biophysica Acta, 1076:406–415 (1991)
J.L. Aikawa, T. Yamashita, Nishiyama, S. Horinouchi & T. Beppu, Effects of glycosylation on the secretion and enzyme activity of Mucor renin, an aspartic proteinase of Mucor pusillus, produced by recombinant yeast, J. Biol. Chem., 265:13955–13959 (1990).
A.-M. Bech & B. Foltmann, Partial primary structure of Mucor miehei protease milk-clotting enzyme, Neth. Milk Dairy J., 35:275–280 (1981).
E. Boel, A.-M. Bech, K. Randrup, B. Draeger, N.P. Fiil & B. Foltmann, Primary structure of a precursor to the aspartic proteinase from Rhizomucor miehei shows that the enzyme is synthesized as a zymogen, Proteins Struct. Funct. Biol., 1:363–369 (1986).
Z. Jia, M. Vandonselaar, P. Schneider & J.W. Quail, Crystallization and preliminary X-ray structure solution of Rhizomucor miehei aspartic proteinase, Acta Crystallogr. Sect. D, 51:243–244 (1995).
C. Thaller, L.H. Weaver, G. Eichele, E. Wilson, R. Karlsson & J.N. Jansonius, Repeated seeding technique for growing large single crystals of proteins, J. Mol. Biol., 147, 465–469 (1981).
Z. Otwinowski, Oscillation data reduction program. In: Data collection and processing: Proceedings of the CCP4 study weekend, 29–30 January, 1993. L. Sawyer, N. Issacs & S. Bailey, eds., Science and Engineering Research Council, Daresbury Laboratory, Warrington, UK (1993).
Collaborative Computational Project #4. The CCP4 suite: Programs for protein crystallography. Acta Crystallogr. Sect. D, 50:760–763 (1994).
M. Baudys, S. Foundling, M. Pavlik, T. Blundell & V. Kostka, Protein chemical characterization of Mucor pusillus aspartic proteinase. Amino acid sequence homology with the other aspartic proteinases, disulfide bond arrangement and site of carbohydrate attachment, FEBS Lett., 235:271–274 (1988).
M. Newman, F. Watson, P. Roychowdhury, H. Jones, M. Badasso, A. Cleasby, S.P. Wood, I.J. Tickle & TL. Blundell, X-ray analysis of aspartic proteinases V. Structure and refinement at 2.0 Å resolution of the aspartic proteinase from Mucor pusillus, J. Mol. Biol., 230:260–283 (1993).
J. Navaza, AMoRe: an automated package for molecular replacement, Acta Cryst. Sect. A., 50:157—163 (1994).
A.T. Brünger, XPLOR Manual Version 3.1. Yale University, New Haven, CT 06511, USA. (1992).
R.J. Read, Improved Fourier coefficients for maps using phases from partial structures with errors, Acta Crystallogr. Sect. A, 42:140–149 (1986).
A.T. Brünger, Free R value: A novel statistical quantity for assessing the accuracy of crystal structures, Nature, 55:472–475 (1992).
R.A. Laskowski, M.W. MacArthur, S.G. Hutchinson & J.M. Thornton, PROCHECK: a new program to check the stereochemical quality of protein structures, J. Appl. Cryst., 26:283–291 (1993).
G.N. Ramachandran, & V. Sasisekharan, Conformation of polypeptides and proteins, Advan. Protein Chem., 23:283–437(1968).
R. Bott, E. Subramanian & D.R. Davies, Three-dimensional structure of the complex of the Rhizopus chinensis carboxyl proteinase and pepstatin at 2.5 Å recresolution, Biochemistry, 21:6956–6962 (1982).
M.N.G. James, A. Sielecki, F. Salituro, D.H. Rich & T. Hofmann, Conformational flexibility in the active sites of aspartyl proteinases revealed by pepstatin fragment binding to penicillopepsin, Proc. Natl. Acad. Sei., 79:6137–6141 (1982).
L. Holm & C. Sander, Protein structure comparison by alignment of distance matrices, J. Mol. Biol, 233:123–138(1993).
N.S. Andreeva & M.N.G. James, Structure and Function of the Aspartic Proteinases: Genetics, Structure, and Mechanisms. Advances in Experimental Medicine and Biology, Vol. 306, Springer Science+Business Media New York, USA. (1991).
T. Yamauchi, M. Nagahama, H. Hori & K. Murakami, Functional characterization of Asp-317 mutant of human renin expressed in COS cells. FEBS Lett., 230:205–208 (1988).
D. Mantafounis & J. Pitts, Protein engineering of chymosin: modification of the pH optimum of enzyme catalysis, Prot. Eng., 3:605–609 (1990).
K.A. Sharp & A. Nicholls, DelPhi V3.0 Manual. Department of Biochemistry and Molecular Biophysics, Columbia University, USA. (1989).
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Quail, J.W., Yang, J., Schneider, P., Jia, Z. (1998). Crystal Structure of The Rhizomucor miehei Aspartic Proteinase. In: James, M.N.G. (eds) Aspartic Proteinases. Advances in Experimental Medicine and Biology, vol 436. Springer, Boston, MA. https://doi.org/10.1007/978-1-4615-5373-1_39
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