Purification and characterization of camel (Camelus dromedarius) milk amylase.
Skimmed camel milk contains 59,900 U/L amylase, which is 39,363 times less than serum and plasma amylase. Camel milk beta-amylase was purified as a 61 KDa band using DEAE-Sepharose and Sephadex G-100 and yielded 561 U/mg. The optimum working pH, Km and temperature were 7.0, 13.6 mg/Lstarch, 30-40 degrees C, respectively. The enzyme has been shown higher affinity toward amylose and soluble starch than glycogen, amylopectin, dextrin, or pullulan. Magnesium chloride, CaCl(2) and NaCl activated the amylase, while EDTA and EGTA decreased its activity. While its activity was increased in the presence of Triton X-100 and Triton X-114. Phenylmethanesulfonyl fluoride did not show any effect on enzyme activity. However, the enzyme activity was inhibited by urea, SDS, DTNB, iodoacetamide, N-ethylmalimide, aprotinin, and trypsin inhibitor. It worked on starch to yield a maltose. Scanning electron microscope images demonstrated a nano-degrading ability on starch granules from various sources (potato, corn, cassava, and rice).
El-Fakharany
Esmail M
EM
Antibody Laboratory, Protein Research Department, Genetic Engineering and Biotechnology Research Institute, New Borg El-Arab, Alexandria, Egypt.
Serour
Ehab A
EA
Abdelrahman
Aref M
AM
Haroun
Bakry M
BM
Redwan
El-Rashdy M
el-RM
D000818:Animals; D007611:Aprotinin / Q000494:pharmacology; D002162:Camelus; D004228:Dithionitrobenzoic Acid / Q000494:pharmacology; D005033:Ethylmaleimide / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D007460:Iodoacetamide / Q000494:pharmacology; D008320:Maltose / Q000138:chemical synthesis / Q000737:chemistry; D008892:Milk / Q000201:enzymology*; D012967:Sodium Dodecyl Sulfate / Q000494:pharmacology; D013213:Starch / Q000737:chemistry; D013696:Temperature; D014508:Urea / Q000494:pharmacology; D001614:beta-Amylase / Q000037:antagonists & inhibitors / Q000302:isolation & purification* / Q000378:metabolism*
D012967:Sodium Dodecyl Sulfate; D008320:Maltose; D014508:Urea; D013213:Starch; D007611:Aprotinin; D004228:Dithionitrobenzoic Acid; D001614:beta-Amylase; D005033:Ethylmaleimide; D007460:Iodoacetamide