Proteins of Crustacean Exoskeletons: I. Similarities and Differences among Proteins of the Four Exoskeletal Layers of Four Brachyurans.

摘要: Most of the proteins extracted from exocuticle, endocuticle, and membranous layer four species anecdysial (intermolt) crabs (the Bermuda land crab Gecarcinus lateralis, rock Cancer antennarius, shield-backed kelp Pugettia producta, southern Taliepus nuttalli) were 31 kDa or smaller; similar Mr common to all three layers. Proteins qualitatively indistinguishable in species. More smaller size pI other exoskeletal layers than larger kDa. epicuticle G. lateralis included a group five ranging 54 42 that bound 45Ca++ vitro. The was not seen exoskeleton or, with exception 44 protein bands C. any exoskeletons During proecdysis, is completely degraded, are preferentially degraded exocuticle endocuticle old which cast as an exuvia at ecdysis. relative amounts extracts (1) (2) exuviae very similar, suggesting there little degradation during proecdysis. Some inner have characteristics those flexible cuticles insects; they acidic pIs form "charge trains," i.e., same separated by differences charge isoelectric focusing.