Stitching the synapse: Cross-linking mass spectrometry into resolving synaptic protein interactions

Synaptic transmission is the predominant form of communication in the brain. It requires functionally specialized molecular machineries constituted by thousands of interacting synaptic proteins. Here, we made use of recent advances in cross-linking mass spectrometry (XL-MS) in combination with biochemical and computational approaches to reveal the architecture and assembly of synaptic protein complexes from mouse brain hippocampus and cerebellum. We obtained 11,999 unique lysine-lysine cross-links, comprising connections within and between 2362 proteins. This extensive collection was the basis to identify novel protein partners, to model protein conformational dynamics, and to delineate within and between protein interactions of main synaptic constituents, such as Camk2, the AMPA-type glutamate receptor, and associated proteins. Using XL-MS, we generated a protein interaction resource that we made easily accessible via a web-based platform (http://xlink.cncr.nl) to provide new entries into exploration of all protein interactions identified.

[Diabetic foot]

Diabetics suffer from a high rate of amputation. Unclear terminology is partially responsible. We offer a clear classification (type A = PAOD; type B = polyneuropathy; type C = combination of A + B). Our classification for plantar ulcer is simple and yields clear indications for appropriate therapy. The operative principles for type B, foot will be discussed (dorsal incision, distal two-thirds resection of metatarsals, proper coverage of bones with soft tissues, necrectomy, placement of Gentamycin-bonded collagen sponge, drainage, primary wound closure, plantar ulcer left untouched). In a collection of 284 treated type B diabetic feet, in only 6% of cases was there secondary wound healing. The plantar ulcer was always cured.