title: Isolation of intact larval haemoglobin from the brine shrimp Artemia salina. Prevention of degradation in vitro by proteases induced during larval development.
abstract: Haemoglobin induced in the larval stage of the brine shrimp, Artemia salina is extensively degraded when isolated from the later developmental stages of the larvae. Alkaline proteases appear in the organism a few hours after the induction of haemoglobin and cause the observed degradation. Addition of 2.6 mM phenylmethylsulphonyl fluoride or 20 micrograms/ml soybean trypsin inhibitor to the extraction buffer used for haemoglobin isolation prevents most of this degradation. Discrete haem proteins are found in extracts of the brine shrimp larvae isolated before induction of the proteases, and the major species has a molecular weight of over 200,000. This is believed to be the native haemoglobin. A spread of lower molecular weight haem-containing polypeptides is found in extracts of larvae isolated after induction of the proteases. These products are believed to result from degradation of the discrete haem proteins present in protease-free extracts.
mesh_terms: D000818:Animals; D001156:Artemia / Q000196:embryology / Q000378:metabolism*; D006454:Hemoglobins / Q000302:isolation & purification*; D007814:Larva; D008970:Molecular Weight; D011480:Protease Inhibitors; D014360:Trypsin Inhibitor, Kunitz Soybean / Q000494:pharmacology
chemical_list: D006454:Hemoglobins; D011480:Protease Inhibitors; D014360:Trypsin Inhibitor, Kunitz Soybean